Chem/Phys Flashcards

Question 1

Q

Solid–> Liquid –> Gas
Enthalpy and entropy pattern

Answer

A

enthalpy increases (least to most heat energy)
entropy increases

Question 2

Q

surfactant

Answer

A

reduces surface tension and total force resisting expansion
decreases work required to expand lungs

Question 3

Q

electrons in smaller orbitals

Answer

A

held more tightly to nucleus
harder to eject, higher energy

Question 4

Q

energy of electron orbit

Answer

A

En= RH/n^2
RH= rydberg constant = 1x10^7 m^-1

Question 5

Q

n

Answer

A

energy level
higher= more energy

Question 6

Q

l

Answer

A

azimuthal/angular momentum
Approximate geometric shape of the orbital
l=n-1

Question 7

Q

ml

Answer

A

magnetic quantum number (spatial orientation)
ml=-l…,0,…,+l

Question 8

Q

ms

Answer

A

spin quantum number (spin orientation)
ms= -1/2 or +1/2

Question 9

Q

electrons within same orbital

Answer

A

are paired and have opposite spins

Question 10

Q

Rutherford

Answer

A

gold foil experiment which showed the atom is actually a ton of empty space with a small positively charged

Question 11

Q

The bohr model

Answer

A

there is a small dense nucleus surrounded by orbiting electrons in different levels (shells) with discrete quanta (essentially energy packets) between them.

Question 12

Q

The heisenberg uncertainty principle

Answer

A

as we know more about momentum of a particle the less you know about its position and vice versa.

Question 13

Q

during decay…

Answer

A

isotopes are formed, but the atomic mass does NOT change

Question 14

Q

gamma rays

Answer

A

weightless packs of energy with no charge

Question 15

Q

electronegativity trend

Answer

A

most at top right

Question 16

Q

atomic radius trend

Answer

A

most at bottom left

Question 17

Q

Polarizability trend

Answer

A

largest on the bottom left (polarizability increases in larger atoms)

Question 18

Q

affinity chromatography

Answer

A

separates molecules based on interactions with stationary phase

column has a high affinity for protein of interest

Question 19

Q

SDS Page

Answer

A

binds anionic detergent to a polypeptide chain
SDS denatures and imparts even charges per mass unit so fractionation occurs by size alone

Question 20

Q

increased length of chromatography column

Answer

A

enhanced resolution

Question 21

Q

reactivity of SN1 mechanism

Answer

A

tertiary (most stable and most favored) > secondary > primary

react faster in polar protic solvents

first order with respect to the electrophile (prenyl bromide) and zero order with respect to the nucleophile (methanol)

Question 22

Q

SN1 steps

Answer

A

2 step reaction
1. leaving group dissociates and leaves behind unstable carbocation (slow/rate determining)
2. Nu- attacks carbocation + produce even mix of enantiomers (racemic)

Question 23

Q

Sn2 steps

Answer

A

Nu- displaces leaving group through a backside attack
R/S becomes inverted
Central C will have 5 substituents

If the electrophile in an SN2 reaction is a chiral center, its stereochemistry will always be inverted by the reaction

Question 24

Q

Reactivity of SN2

Answer

A

primary favored– steric hinderance is limiting

favors polar, aprotic solvents (acetone/DMSO)

Question 25

Q

Lowest priority should be

Answer

A

Dashed (in towards page)
if not, switch R and S

Question 26

Q

Galvanic cells

Answer

A

have NEGATIVE ΔG
Utilize spontaneous redox reactions to produce electrical potential

Question 27

Q

ΔG Equation

Answer

A

ΔG° = -nFE°

The Gibbs free energy ΔG° of an electrochemical cell is related to the number of electrons n transferred in the overall reaction, the overall cell potential = E°cell, and Faraday’s constant F.

Question 28

Q

E cell

Answer

A

E cathode - E anode
E reduced - E oxidized

Question 29

Q

Capacitance

Answer

A

Ability to hold charge

C = q/v

Ratio of magnitude of the charged stored on one plate (pos charge) to the potential difference across the capacitor on the other plate (neg charge)

C =(ϵ0 ϵr A)/d.

C=ϵ0 A / d:

ϵ0is the permittivity of free space (8.85 x 10-12 F/m)

directly proportional to area and charge but inversely proportional to the distance between the two sides of the capacitor.

Question 30

Q

Heart Rhythm Control

Answer

A

SA node of the right atrium sends out action potentials which use gap junctions to propagate through tissue and contract
Action potential flows from SA node to atria
Atria contracts and sends blood to ventricles, which push blood out of the heart
Signal sped through bundle of His and Purkinje fibers to muscle cells of ventricle

Deoxygenated blood returns to right atrium via superior and inferior vena cavae and coronary sinus (drains coronary veins)
then, pumped into right ventricle through tricuspid valve
from right ventricle to pulmonary arteries through the pulmonary semilunar valves
After oxygenation, returned to heard via pulmonary veins and enters left atrium
Pumped through bicuspid valve from the left atrium to left ventricle which pushes blood into circulation

Question 31

Q

Phosphoric Acid

Question 32

Q

Phosphorous Acid

Question 33

Q

Ammonium

Question 34

Q

Ammonia

Question 35

Q

Common Ion Effect

Answer

A

pre existing presence of an ion in solution reduces molar solubility of a substance containing that ion

Ex. If you add NaCl to a solution already containing MgCl, it will not dissolve as well and will precipitate more

the decrease in solubility of an ionic precipitate by the addition to the solution of a soluble compound with an ion in common with the precipitate.

Question 36

Q

Ksp

Answer

A

the product of each substance’s dissolved ion concentration raised to the power of the stoichiometric coefficient (larger= more soluble)

Question 37

Q

Hooke’s Law

Question 38

Q

Potential Energy of a spring

Answer

A

1/2 kx ^2

Question 39

Q

Charles’ Law

Answer

A

Direct relationship between gas’ volume and temp

if one increases, the other will too

Question 40

Q

physics formulas

Answer

A

d=vt
vf = vi + at
d = vit + 1/2 at^2
vf^2 = vi^2 + 2ad

Question 41

Q

1 atm in Pa

Question 42

Q

PE and KE

Answer

A

(1/2) m (vf)^2 = mgΔH

Question 43

Q

Homotropic Regulation

Answer

A

when a molecule serves as a substrate for its target enzyme and regulates enzyme activity

Question 44

Q

volume of gasses

Answer

A

changes as a result of pressure changes

Question 45

Q

solubility of water vapor in air

Answer

A

decreases with decreasing temperature

decreased temp, decreased relative humidity (can hold less water)

Question 46

Q

1 mol ideal gas

Answer

A

occupies 22.4 L

Question 47

Q

Titration equation

Answer

A

NaVa=NbVb
N= mol/L

Question 48

Q

Agonist

Answer

A

chemical that binds to a receptor and activates a biological response

Question 49

Q

positive controls

Answer

A

known to produce expected effect

Question 50

Q

PE

Answer

A

mgh
in joules

Question 51

Q

Wnet

Answer

A

ΔKE
in joules

Question 52

Q

Power (Watts)

Answer

A

Work (kJ) / Time (s)
W / t

Question 53

Q

Coulomb’s Law

Answer

A

Electrostatic force between 2 charged particles is proportional to individual charges and inversely proportional to the square of the distance
FE= k q1 q2 / r^2

Question 54

Q

transition metals

Answer

A

create colored solutions because they have unfilled d orbitals

Question 55

Q

pI (isoelectric point)

Answer

A

1/2 (pka1 + pka2)

Question 56

Q

inert gases

Answer

A

Ex. N2
Don’t react with oxygen or other gases, prevent side chain reactions

Question 57

Q

hydronium conc. > 1M

Answer

A

pH in negatives becomes possible

Question 58

Q

Protein synthesis

Answer

A

from N –> C

Question 59

Q

Solute concentration increase (in boiling systems)

Answer

A

Causes a decrease in the rate at which water molecules escape the liquid surface

Question 60

Q

Boiling point

Answer

A

where Pvap = Patm

Question 61

Q

Beta minus decay

Answer

A

move 1 right on periodic table

Question 62

Q

Beta plus decay

Answer

A

Move 1 left on periodic table
same for e capture

Question 63

Q

Alpha decay

Answer

A

Move 2 left on periodic table
Charge -4 on top

Question 64

Q

Torque formula

Answer 58

A

the substrate concentration at which the reaction rate is half of its maximal value

Answer 59

A

the rate attained when the enzyme sites are saturated with substrate

Answer 60

A

at rest, stay at rest
F = ma
every action has equal and opposite reaction

Answer 61

A

In parallel= C1+C2+C3+…
In series= 1/C1+1/C2+1/C3+…

Answer 62

A

In parallel= 1/R+1/R2+…
In series= R1+R2+R3+…

Answer 63

A

catalyzes aldehydes to alcohols

Answer 64

A

used for oxidative cleavage of alkenes

Answer 65

A

NaCr2O7
KMnO4

Answer 66

A

for reduction of aldehyde to primary alcohol

LiAlH4 is a strong reducing agent and will reduce carbonyl compounds, including esters and carboxylic acids, to alcohols.

Reducing agents decrease an atom’s oxidation state and reduce the number of bonds carbon has to electronegative atoms while increasing the number of bonds to less electronegative atoms (commonly hydrogen).

Answer 67

A

@ around 3000

Answer 68

A

@ 3300-3500 (broad)

Answer 69

A

@ around 2200

Answer 70

A

@ 1700 (sharp)

Answer 71

A

must possess a highly positive standard reduction potential because it is the final e- acceptor

Answer 72

A

will be opposite

Answer 73

A

Release heat

Answer 74

A

absorb heat

Answer 75

A

H reaction = H products - H reactants

whether taking place in one step or multiple

Answer 76

A

uses electric potential to drive a spontaneous redox reaction

Answer 77

A

uses conducting material between plates

Answer 78

A

If buffer is acidic, will want a weak acid as reagent
If buffer is basic, will want a weak base as reagent

Answer 79

A

Light travels from more to less dense medium and can no longer refract

angle of incidence will be greater than the critical angle

only happens when n1>n2

Answer 80

A

Water soluble, surface active compounds that increase solubility of poorly soluble drugs

Answer 81

A

Attenuation= weakening of ultrasound signal
parts of the signal are reflected, scattered, absorbed, refracted, or diffracted

Answer 82

A

donators
Generate a higher inductive effect

Answer 83

A

can act as an acid or a base
ex. sodium bicarbonate NaHCO3 can dissociate into NAOH or HCO3-

Answer 84

A

output work/input energy

Answer 85

A

the distance the compound migrated divided by the distance of the solvent front

Answer 86

A

Silica gel is polar and hydrophilic while mobile phase is usually a moderately polar, organic solvent
- non polar compounds dissolve in the organic solvent and move faster and further

Mnemonic: no problem fuck face (non polar faster further)

Dependent on polarity, temperature, eluting strength (increases with increasing solvent polarity)
- polar compounds will not move as far, nonpolar will have more affinity for mobile phase
- temp inversely proportional to eluting strength

Answer 87

A

Will have a pKa within 1 value of the pH

Answer 88

A

results in a new carbon–carbon bond and an α,β–unsaturated enone. The reaction requires two carbonyl groups (from ketones and/or aldehydes) and occurs by the nucleophilic attack of an enolate on a carbonyl followed by elimination

base pulls of a hydrogen to form a carbanion
carbanion attacks carbonyl to create C-C bond
an elimination reaction with heat removes alcohol and adds alkene

Answer 89

A

the more stable product will predominate

Answer 90

A

the intramolecular reaction between an alcohol and a carboxylic acid that creates a cyclic ester (lactone).

Lactonization can be classified as both a dehydration reaction and a condensation reaction, as a molecule of water is lost when the two functional groups combine to form a lactone. Lactonizations that result in the formation of five- or six-membered rings are especially favorable.

Answer 91

A

occurs when a substance gains electrons or decreases the number of carbon-heteroatom bonds (carbon to something other than carbon) at a specific carbon atom.

Answer 92

A

an intramolecular condensation reaction between an amine and a carboxylic acid that forms a cyclic amide (lactam).

Answer 93

A

results in the preferential formation of a stereoisomer. For example, a reaction that prefers either a cis or trans outcome would be stereoselective.

Answer 94

A

structures that have the same connectivity and can be interconverted by the rotation of σ bonds. Because conformational isomers are identical except for bond rotations, they are the same compound.

Answer 95

A

have the same molecular formula but differ in connectivity

Answer 96

A

nonsuperimposable mirror images in which all stereocenters are inverted.

have same chemical properties, but differ in how they rotate the plane of polarized light

Answer 97

A

stereoisomers with two or more chiral centers in which some, but not all, of the chiral centers are opposite.

have very similar chemical, but less similar physical properties,

Answer 98

A

determined by the expression 2^n, where n is the number of stereocenters.

Be careful of meso compounds!

Answer 99

A

U= 1/2 C V^2

Answer 100

A

measures the voltage V between two points in an electric circuit. To measure V across a resistor, the voltmeter is connected in parallel with the resistor because circuit elements connected in parallel have the same V. By Ohm’s law, the resistor’s V equals the product of the current I and the resistance R: V=IR

should behave like an open circuit (ie, have a very large resistance) to ensure accurate voltage measurements

Answer 101

A

depends on Coulomb’s constant k and the distance r from q, according to the equation:

E= kq / (r^2)

Answer 102

A

an equilibrium constant (Keq) > 1 corresponds to a negative ∆G. This makes logical sense, since Keq > 1 indicates that the reaction favors the products, while ∆G < 0 tells us that the reaction is spontaneous as written

Answer 103

A

occurs when ΔH<0 and ΔS>0.

Answer 104

A

Vitamin E

Answer 105

A

when water is able to bond with hydrophilic (polar) residues

Answer 106

A

so does the strength of intermolecular forces between molecules.

Answer 107

A

occurs as the lone pair of electrons on the nitrogen atom on the amine attacks, and the amine adds to the carbonyl carbon, making it a nucleophilic acyl substitution.

In the process of bond formation, the hydroxyl group of the carboxylic acid leaves as a water molecule. Therefore, this is a condensation reaction

Answer 108

A

a motor protein that walks towards the minus end of the microtubules, which is oriented towards the center of the cell.

Movement toward the center of the cell is described as retrograde.

Answer 109

A

a motor protein that is responsible for anterograde transport in cells.

Answer 110

A

a motor protein that is primarily responsible for attaching to actin filaments during muscle contractions.

Answer 111

A

a class of cell adhesion molecules (CAM) that mediate the inflammatory response, and is not a motor protein.

Answer 112

A

n = c/vmaterial

This value is 1 for a vacuum and is approximated as 1 for air. For all other materials, n is greater than 1; for instance, window glass has a refractive index of 1.52.

Answer 113

A

n1sin(θ1) = n2sin(θ2)

Answer 114

A

(Ex. moving from water to air)
the angle θ with the normal will increase—in other words, the ray of light will bend further away from the normal.

Answer 115

A

As the angle of the incident ray (θ1) increases, there will come a point where the angle of the refracted ray (θ2) reaches 90°

When angle increases beyond critical angle, the light can no longer refract at all and instead are reflected within the original medium (total internal reflection)

Answer 116

A

solubility product constant

equilibrium constant for a solid substance dissolving in an aqueous solution

more soluble= higher Ksp value

Answer 117

A

Ksp = [products] ^ # molecules

ex. Ca(OH)2

Ksp = [Ca] [OH]^2
Ksp = x(2x)^2

set Ksp = 4x^3

Answer 118

A

will NOT change from changes in concentration (though concentration may affect whether a precipitate forms)

will only change by changing temperature

Answer 119

A

increasing the temperature will shift the reaction toward the products, while decreasing it will shift the reaction toward the reactants

Answer 120

A

If a sample has nuclear spin due to an odd number or protons or neutrons, will be affected by magnetic field

Atomic nuclei may align with the field (low energy) or against the field (high energy)

Answer 121

A

resonance frequencies are chemical shifts ranging from 0 on the far right to positive values on the far left

shift of 0 is assigned to TMS as a refernce point

peaks shifted to the right are upfield

peaks shifted to the left are downfield

Answer 122

A

the distinct peaks (groups of hydrogens) created by hydrogens

Answer 123

A

hydrogens that are different than others in molecule (will not be unique if there are lines of symmetry)

Answer 124

A

how many individual peaks will be within a signal
n+1 where n = # of adjacent hydrogens

Answer 125

A

how far away a signal is from 0 (on right @ TMS)

depend on electronegative atoms and unsaturated groups
- closer to electronegative atom/unsaturated groups will be downfield (further left) - downfield and de-shielded (When electronegative groups are present, they pull electron density away from the proton and further deshield it.)

Answer 126

A

4000-2500= single bond region
2500-2000= triple bond region
2000-1500= double bond region

Answer 127

A

@ around 3000

Answer 128

A

hydrochloric acid
nitric acid

Answer 129

A

Hydrofluoric acid
Acetic acid

Answer 130

A

compounds with negative charges will be attracted to stationary phase and move slowly through column

compounds with positive charge will repel and elute through more quickly

Answer 131

A

Matter is exchanged; heat E can be exchanged

Answer 132

A

No matter is exchanged; heat E can be exchanged

Answer 133

A

No matter is exchanged; no heat E is exchanged

Answer 134

A

the internal energy of an isolated system is constant

Inability to create or destroy matter

Energy cannot be added/taken away but can be converted into forms like heat or work

Answer 135

A

transfer of energy that can cause a change in pressure or volume

Answer 136

A

Implies that phase change is consuming energy

either melting, evaporation, or sublimation

Answer 137

A

Implies that phase change is releasing energy

either freezing, vaporization, or deposition

Answer 138

A

Q= heat change
m= mass
L= specific latent heat

Answer 139

A

(1) loss of an electron
(2) increased oxidation state
(3) loss of a C–H bond (e.g. alkane → alkene)
(4) gain of a C–O or C–N bond (or any bond between carbon and a highly electronegative atom)

Answer 140

A

(1) gain of an electron
(2) decreased oxidation state
(3) formation of a C–H bond (e.g. alkene → alkane)
(4) loss of a C–O or C–N bond (or any bond between carbon and an electronegative atom).

Answer 141

A

from alcohols (most reduced/least oxidized) to aldehydes/ketones (intermediate reduction/oxidation) to carboxylic acids (least reduced/most oxidized)

Answer 142

A

come in pairs and typically contain one or more chiral centers.

These substituents are arranged differently around the chiral carbon, in such a way that the molecule cannot be rotated to make the two arrangements match

Answer 143

A

highest priority groups on the same side of the molecule

Answer 144

A

the cleavage of an alkene or alkyne with ozone (O3) that results in the multiple carbon–carbon bond being replaced by a double bond to oxygen (carbonyl)

Answer 145

A

a logarithmic scale expressing the intensity of a sound as its ratio to that of the smallest detectable sound intensity I0). The intensity ratio of sound in decibels is defined as dB = 10log(I/I0), where I0 is 1 × 10−12 W/m2.

Answer 146

A

from 20 Hz to 20 kHz

Answer 147

A

Strecker synthesis is used to generate amino acids by reacting an aldehyde with a desired R group.

Gabriel synthesis can be used to generate primary amines, which can then be immediately followed-up with malonic ester synthesis to create an amino acid.

Answer 148

A

f = (1 / 2 π)(√k / m)

Answer 149

A

produce myelin in the CNS

Answer 150

A

produce myelin in the PNS

Answer 151

A

Compared to the neutral atom of a given element, its cation will be smaller but its anion will be larger.

Answer 152

A

Metal cations with a smaller ionic radius and a higher positive charge are stronger Lewis acids (electron acceptors) than those with a larger ionic radius and lower charge.

Answer 153

A

Use when you have equivalent constant

Answer 154

A

are composed of a carbon-nitrogen double bond with either a hydrogen atom or an R group attached to the nitrogen atom.

Answer 155

A

a carboxylic acid derivative with a carbonyl carbon atom bonded to an amine group, as opposed to a hydroxyl group.

Answer 156

A

functional groups that contain an amine group bonded to an alkene. Many imines can be converted to enamines through tautomerization.

Answer 157

A

a functional group with a nitrogen atom bound to two acyl groups (ie, two carbonyl carbon atoms). Imides are structurally similar to acid anhydrides but include bonds with the acyl groups instead of oxygen atoms.

Answer 158

A

To visually detect when a titration is complete, an indicator that has an endpoint (color change) near the pH of the equivalence point can be added to the solution. Different indicators change color across a particular pH range (endpoint range). The best indicator for a given titration is one that has a pH range that corresponds most closely to the pH of the equivalence point.

Answer 159

A

The halogens are generally good leaving groups because they can form stable anions. Larger halogens are better leaving groups than small halogens because they can spread the negative charge over a larger surface area.

Answer 160

A

Acids catalyze many reactions by donating protons to a reactant. Protonation enhances electrophiles and increases the stability of leaving groups. Acids generally decrease the nucleophilicity of molecules.

Answer 161

A

The Gabriel synthesis is a method used to make primary amines, including α-amino acids with potassium phthalimide and diethyl bromomalonate, (starting materials that have planar reaction sites without chiral centers).

postassium phtalimide acts as a nucleophile and attacks electrophilic C of diethyl bromomalonate in an SN2 reaction where Br leaves. Then, in another SN2 reaction, the α-carbon is deprotonated with a base and attacks an alkyl halide to add the amino acid side chain.Hydrolysis of the phthalimide group and the esters on the α-carbon is followed by acidification of the carboxyl groups and decarboxylation, yielding an amino acid.

Although the decarboxylation step creates a stereocenter, this step is not stereospecific and causes the Gabriel synthesis to yield a mixture of enantiomers (R and S aas).

Answer 162

A

creates a mixture of diastereomers

Answer 163

A

Uses a chiral stationary phase that interacts more strongly with one enantiomer while the other moves more quickly through the column

Answer 164

A

performed under reduced system pressure, thereby lowering a compound’s boiling point.

Compounds with high boiling points (>150 °C) tend to decompose at or near their boiling point. Therefore, vacuum distillation is ideal for compounds with a boiling point over 150 °C to prevent degradation

Answer 165

A

ideal for compounds with boiling points less than 25°C apart and less than 150°C

the initial distillate will be enriched in the lowest boiling point that was placed in the flask. highest boiling point will be in the final fractions

Answer 166

A

if the components have widely different boiling points (greater than a 100 °C difference in boiling points).Aug 11, 2020

Answer 167

A

a technique that separates compounds based on boiling point. Compounds with lower boiling points have shorter retention times than compounds with higher boiling points. For compounds with a similar number of carbon atoms, the boiling point depends on the functional group and the strength of intermolecular forces present.

branching (decreases surface area and increases steric hinderance) decreases the boiling point

Answer 168

A

separates molecules according to their relative polarity and the resulting interactions with the mobile and stationary phases.
nonpolar compounds elute faster than polar (nonpolar compounds have a shorter retention time, and polar compounds have a longer retention time.)

think of “like dissolves like” principle; nonpolar compounds more closely interact with nonpolar, vice versa

on a chromatogram, the area under the curve is proportional to the quantity of material present

In reversed-phase HPLC, the mobile phase is a polar solvent and the stationary phase is made of a nonpolar material. (polar molecules will move up the most)

the stationary phase is polar relative to the mobile phase. Molecules with more polar bonds have a greater affinity for the stationary phase, and thus have a longer retention time than molecules with fewer polar bonds

Answer 169

A

a technique that uses an organic solvent and an aqueous solution to separate molecules based on solubility. Molecules have a greater affinity for solvents with similar polarity (“like dissolves like”).

Modifying a molecule’s charge or polarity changes its affinity for the organic or aqueous layer.

Answer 170

A

An endothermic reaction has a positive ΔH° and absorbs heat from the surroundings

An exothermic reaction has a negative ΔH° and releases heat into the surroundings.

Answer 171

A

When ΔS° is positive and ΔH° is negative (ie, an exothermic reaction), the process is always spontaneous (−ΔG°).

When ΔS° is negative and ΔH° is positive (ie, an endothermic reaction), the process is nonspontaneous (+ΔG°) at any temperature.

When both ΔS° and ΔH° are negative, the process is spontaneous (−ΔG°) at low temperatures and nonspontaneous (+ΔG°) at high temperatures.

When both ΔS° and ΔH° are positive, the process is spontaneous (−ΔG°) at high temperatures and nonspontaneous (+ΔG°) at low temperatures.

Answer 172

A

can be estimated as the sum of the atomic radii of the bonded atoms

Answer 173

A

a lab technique to separate materials based on differences in solubility.

Liquid-liquid extraction requires liquids that are not soluble in one another (immiscible) and form two distinct layers when placed in a container.

Extraction liquids typically have different polarities, and dissolved solute(s) partition between the two layers based on the principle of “like dissolves like.”

Answer 174

A

Amides, amines, and compounds that contain an odd number of nitrogen atoms have a molecular ion with an odd m/z and fragments with an even m/z.

Some alcohols are prone to dehydration, where the molecular ion is apparent 18 m/z below the expected value.

Chlorinated and brominated compounds have peaks determined by their natural isotopic abundance.

Answer 175

A

measures the direction (+ or −) and magnitude (angle) of rotation by which chiral molecules rotate plane-polarized light.

Answer 176

A

the instrument used to measure the rotation of polarized light.

Answer 177

A

= observed rotation / (c x l)

c is concentration in g/mL
l is path length in dm

Answer 178

A

hydrolyzable lipids that contain an ester bond formed by the linkage between a long-chain fatty acid and a long-chain alcohol.

Answer 179

A

populated starting with lowest energy MO

HOMO= highest occupied molecular orbital
LUMO= lowest unoccupied molecular orbital

conjugation (more stable, lower energy)–
- decreases the HOMO-LUMO energy difference
- increases the λmax

molecules with a smaller gap between HOMO and LUMO are more easily excited and can absorb longer wavelengths

Answer 180

A

E = h f

E = h c / λ

Answer 181

A

the m/z value that produces the highest relative abundance (100%) and normally corresponds to a cation that is either especially stable or likely to form.

Mass spectrometry experiments ionize samples and detect the abundance of ions at each mass-to-charge ratio (m/z).

Answer 182

A

in IR spec, wavenumbers from 1500 - 400 cm-1

Answer 183

A

the more a protons electron density is pulled away (by more electronegative elements), the less it can shield itself from the applied magnetic field.

Answer 184

A

Two solvents must be immiscible – form two layers and do not mix.

Aqueous phase: polar layer, usually water
Organic phase: nonpolar layer

Separatory Funnel: equipment used to isolate the two phases after they have been given time to spread out again.
Denser layer sink to the bottom due to gravity, and can be removed.

More common for organic layer to be on top, but ultimately depends on density.

Once the desired product has been isolated, it can be obtained by evaporating the solvent by using a rotary evaporator.

Wash: reverse of the extraction process in order to remove unwanted impurities.
Small amount of solute is used to extract and remove impurities

Answer 185

A

extraction
filtration
recrystalization

Answer 186

A

separates molecules primarily on the basis of boiling point.
Compounds with a lower boiling point tend to stay in the gas phase and move through the column quickly, whereas compounds with higher boiling points have a greater tendency to interact with the liquid phase and a longer retention time.

For compounds with the same number of carbon atoms, alkanes have the lowest boiling point, followed by aldehydes and ketones, alcohols, and carboxylic acids.

eluent is a gas instead of a liquid
mobile phase is usually an inert gas

compounds must be volatile (low melting point, sublimable, vaporizable)

Answer 187

A

Identify the Longest Carbon Chain Containing the Highest-Order Functional Group
The highest priority functional group (with the most oxidized carbon) will provide the suffix
If there are two or more carbon chains of equal length, then the more substituted chain gets priority as the parent chain.
Number the Chain
The carbon numbered one will be the one closest to the highest-priority functional group.
If the functional groups all have the same priority, numbering the chain should make the number of the substituted carbons as low as possible
The more oxidized a carbon is, the higher priority it has in the molecule.
Oxidation state increases with more bonds to heteroatoms (atoms beside hydrogen and carbon) and decreases with more bonds to hydrogen.
For rings, numbers start at the point of greatest substitution, and continues in that direction
If there is a tie between assigning priority in a molecule with double and triple bonds, the double bond takes precedence.
Name the Substituents
Substituents are functional groups that are not part of the parent chain.
Substituents name will be placed at the beginning of the compound name as a prefix, followed by the name of the longest chain.
Only the highest priority functional group will determine the suffix for the compound
Carbon chain substituents are named like alkanes, with suffix –yl replacing –ane
n- prefix indicates that it is normal or is a straight chain alkane.
If there are multiple substituents of the same type, prefixes such as di-, tri- & tetra- are used.
Assign a Number to Each Substituent
Pair the substituents that you have named to the corresponding number in the parent chain
Multiple substituents of the same type will get both the required prefix and a carbon number designation, even if they are on the same number
Complete the Name
Always begins with the names of the substituents in alphabetical order, and each substituent is preceded by its number.
Numbers are separated by commas, and word with hyphens
Name is finished with the name of the parent chain with the suffix being the functional group of the highest priority.

Answer 188

A

Simple hydrocarbons with the formula: CnH2n+2
Goes methane, ethane, propane, butane, pentane, hexane, heptane, octane….
Alkyl halides are alkanes with halogen substituents (common). Have the following prefixes: fluoro-, chloro- , bromo-, or iodo-.

Answer 189

A

indicated by the lower number carbon that precedes the bond

Answer 190

A

carbon attached to hydroxyl group gets the lowest possible number

hydroxyl groups on same carbon: germinal diols
hydroxyl groups on adjacent carbons: vicinal diols

Answer 191

A

contain a carbonyl group; are chain terminating (carbonyl appears at the end of the chain)

replace -e with -al (aldehyde) or -one (ketone)

aldehydes: carbonyl takes precedence and is given the number
ketones: list alkyl groups in order then end with ketone

Answer 192

A

Includes enthalpy, entropy, and Gibbs free energy; means they describe the energetic differences between the reactants and the products in their current state. These values are independent of the chemical pathway that a reaction takes to get from reactants to products.

Answer 193

A

(or path functions) describe the path taken by a system to transition from one equilibrium state to another. A system transitions from one state to another due to a net flow of energy in the form of heat transfer or work. For example, the loss or gain of heat is a process function because it describes the path taken by a system from its current pressure, volume, and temperature to a different set of values.

Answer 194

A

when light of a sufficiently high frequency is incident on a metal in a vacuum, the metal atoms emit electrons

electrons produce a current (more intense light, more electrons on electrode, larger current)

Answer 195

A

minimum frequency of light that causes ejection of photons

if frequency of photon is more, electron will be ejected with kinetic energy:
Kmax = hf - W

Answer 196

A

difference between theoretical mass of a nucleus and the actual mass; actual mass is smaller (since some has been converted into speed of light)

Answer 197

A

allows nucleons to bind in the nucleus; bonded nucleons have lower energy than unbonded constituents; difference is emitted as radiation

higher binding energy= more stable nucleus

Answer 198

A

When parent nucleus, X, undergoes nuclear decay to form daughter nucleus Y, the balanced reaction is: ZAX=Z’A’Y+emitted decay particle

Answer 199

A

∆n/∆t=-λn

n=n0e^-λt

Answer 200

A

in Siemens/m (vs. conductance which is in Siemens)

measures how well electrons can flow

metallic or electrolytic
electrolytic occurs in an ionic solution when electrodes are placed in an electrolyte solution and a voltage is applied; electrolyte will conduct electricity

Answer 201

A

I entering at junction= I exciting from junction

must have the same amount of charges going in and out

When a resistor is removed from a series circuit, there is a larger voltage drop across the remaining resistors.

Answer 202

A

internal charge cannot flow freely and cannot conduct electric current; does NOT transmit heat/sound/electricity

Answer 203

A

the property of a material quantifying how strongly it resists or conducts current; low resistivity indicates ready flow of electric current

p (resistivity) = R x A / L
R= resistance
L = length (if length increases, resistance increases)
A= area (increases number of conduction pathways which reduces resistance)

Answer 204

A

Resistivity: intrinsic resistance
Length: longer= increased resistance
Cross Sectional Area: increases number of conduction pathways and reduces resistance
Temperature: typically greater resistance at higher temperatures; increases thermal vibration to increase resistance to e- flow

Answer 205

A

P= I V =I^2 X R = V^2 / R

Answer 206

A

U=1/2CV^2

Answer 207

A

Similar to insulation; will always INCREASE capacitance when placed between the plates, never decreases capacitance

Q=CV

For an isolated and charged capacitor, Q is constant because there’s no battery source that can add any further charge. Since C increases with dielectric, V must decrease.

For a charging capacitor, V is constant and equal to the voltage of the battery source. Since C increases with the dielectric, Q must increase.

Dielectrics are a class of polarizable materials in which electric dipoles can be induced. When a dielectric material is inserted between capacitor plates, the electric field present between these plates causes the dipoles induced in the dielectric material to align, decreasing both electric field strength and voltage. Due to this insulating effect, dielectric substances increase capacitance.

Answer 208

A

Ammeters: measure CURRENT at some point within a circuit; circuit must be on and must be put in series with current voltage to be measured; ideal ammeters have 0 resistance and no voltage drop

Voltmeters: requires circuit to be on, uses magnetic properties of current carrying wires; measures VOLTAGE drop across two points in a circuit that must be wired in parallel; ideal voltmeter would have infinite resistance

Ohmmeters: don’t require circuit to be on; have their own battery w/ known voltage; acts like an ammeter to find RESISTANCE

Answer 209

A

68% of the population is within 1 standard deviation of the mean.
95% of the population is within 2 standard deviation of the mean.
99.7% of the population is within 3 standard deviation of the mean

only applies for normal distribution

Answer 210

A

third quartile minus first quartile

Answer 211

A

type I : incorrectly rejecting the null hypothesis (think it’s wrong when right)
type II : incorrectly fail to reject null hypothesis (think it’s right when wrong)

Answer 212

A

will not evenly distribute charge over surface or transfer charge well

Answer 213

A

will distribute any charge approximately evenly across the surface

Answer 214

A

they are very stable, and are strong bases
will not participate in nucleophilic substitution unless they are replacing a great leaving group (Cl/Br)

Answer 215

A

more stable stacking of trans fats means that they are more likely to be solids—and therefore less likely to be liquids—at room temperature.

Answer 216

A

involves the conversion of fat or oil or lipid into soap and alcohol by the action of heat in the presence of aqueous alkali

the hydrolysis of an ester with a strong base

Answer 217

A

monoglyceride or triglyceride that combines with phosphoric acid to form a phospholipid

Answer 218

A

any compounds with varying hormone-like effects; notably the promotion of uterine attraction

cyclic fatty acids

Answer 219

A

E = hv/λ

(comes from v = λf)

Answer 220

A

6.02 x 10^23 mol-1

Use when wanting to convert moles to molecules

Answer 221

A

During the ionization of transition metals, electrons from 4s subshell orbitals are generally removed before those from 3d subshell orbitals.

ex. ionization of Co 2+ is [Ar]3d7

Answer 222

A

Diatomic elements have oxidation states of zero. Otherwise, oxidation states are summed to equal the charge of the molecule.

The oxidation state of F is -1, because it is the most electronegative element. Other halogens will usually have an oxidation state of -1, unless they are bonded to a more electronegative halogen, N, or O. In that case, their oxidation state may be +1, +3, +4 (for Br), +5, or even +7.

The oxidation state of H is +1, except when it is bonded to a more electropositive element, in which case it will be -1. The examples you are most likely to encounter of this on the MCAT are the reducing agents NaH, NaBH4, and LiAlH4.

The oxidation state of O is usually -2, with some important exceptions, such as peroxides, in which it is -1.

The oxidation state of alkali metals (the first column in the periodic table) is always +1, and that of alkaline earth metals (the second column in the periodic table) is always +2.

Answer 223

A

Peaks that appear between 0-5 ppm are indicative of sp3 hydrogens.

Peaks around 5-8.5 ppm are indicative of amide (R(C=O)NR2) hydrogens.

Answer 224

A

Enols are alkenes with a hydroxyl group attached to one of the double bonds’ carbon atoms.

Enolates are the deprotonated anions of enols.

Answer 225

A

180 g (C6H12O6)

Answer 226

A

a measure of the stiffness of an elastic solid material. The slope of the graph (stress/strain) is equal to the Young’s modulus. The higher the Young’s modulus, the stiffer the solid material is.

Answer 227

A

E = h x f

Answer 228

A

due to shear forces (friction) between the fluid and the solid surface of the tube. This results in layers having a gradient of velocities, in which:

flow is the fastest in the middle of the tube (where friction is low) and slowest near the surface (where friction is high).

Answer 229

A

Q = (ΔP x pi x r^4) / (8ηL)

the flow rate (Q), the pressure drop between both ends of the tube (∆P), the radius of the tube (r), the length of the tube (L), and the viscosity (η)

Answer 230

A

there is less oxygen in the air

Answer 231

A

Fnet = ma = Fapplied – Fk, where Fk is the force of kinetic friction

F applied = ma

if you want to convert to Work,
W= Fd cosΘ

Answer 232

A

slowly establishes equilibrium between the dissolved carbon dioxide and carbonic acid (H2CO3), which is a weak acid that would lower the pH

Answer 233

A

an acid-catalyzed reaction of an alcohol with a carboxylic acid

The Fischer esterification requires an acid catalyst (usually sulfuric acid, H2SO4) and heat, and is a condensation reaction that eliminates a molecule of water from the reactants alongside ester formation.

Answer 234

A

named by first stating the prefix that corresponds to the alcohol alkyl chain followed by the name of the carboxylic acid. The carboxylic acid suffix –ic acid is replaced by –ate.

Answer 235

A

Boiling points are dependent on a molecule’s intermolecular forces, and strong intermolecular forces lead to higher boiling points.

Carboxylic acids contain a hydrogen bond donor (hydroxyl hydrogen) and hydrogen bond acceptors (carbonyl oxygen, hydroxyl oxygen), and therefore can hydrogen bond with themselves. Because hydrogen bonds are strong intermolecular forces, carboxylic acids have higher boiling points than molecules of a similar molecular weight that cannot hydrogen bond to themselves and have weaker intermolecular forces.

Answer 236

A

stop codons are recognized by release factors, not tRNA molecules. Therefore, the last tRNA brought into the ribosome binds the codon directly upstream of the stop codon

Stop codons do not code for amino acids and are recognized by release factors instead of tRNA

Answer 237

A

Changes in respiration affect blood pH levels, with increased respiration tending to cause increased blood pH.

Answer 238

A

equal to the liquid density multiplied by the gravitational acceleration multiplied by 10 cm.

Answer 239

A

release of heat energy

Answer 240

A

a five-membered aromatic heterocycle containing one nitrogen atom.

found in heme

Answer 241

A

vπ r^2 = vπ r^2
v= velocity
r= radius
characterizes flow

Answer 242

A

group attached to histidine

formula: C3N2H4 (cyclic with 2 amine)

Answer 243

A

group attached to tryptophan

formula: C11H12N2O2 (two rings with an amine)

Answer 244

A

Ammonium formate is NH4HCO2

Ammonium carbonate is (NH4)2CO3

Ammonium bicarbonate is NH4HCO3

Ammonium acetate is NH4CH3CO2

Answer 245

A

energy to be overcome before forming products

Answer 246

A

An esterification reaction results in the formation of a new ester linkage. Direct esterification reactions between a carboxylic acid and an alcohol occur slowly at room temperature and in the absence of a catalyst.

Answer 247

A

organic anions derived from the deprotonation of carbonyl compounds

Answer 248

A

retro-aldol reaction is the reverse of an aldol condensation. When heated and treated with an aqueous base, the dehydration product (enone or enal) is first hydrated into the aldol product (β-hydroxy ketone), and then the carbon-carbon bond between the α- and β-carbons breaks. The retro-aldol reaction yields two products: either two ketones, two aldehydes, or one of each.

Answer 249

A

the pH value at which the protonated and deprotonated forms of the functional group are present in equal concentrations.

Influenced by local environmental and structural factors that affect the stabilities of the protonated vs. deprotonated forms.

If the protonated form is stabilized, the functional group resists deprotonation until higher pH values, raising the pKa.

Destabilization of the deprotonated form allows the group to pick up a proton more easily, raising the pH at which significant protonation can occur, and thus raising the pKa.

Answer 250

A

the linkage between monosaccharides and is made up of a hemiacetal or hemiketal from one sugar and the hydroxyl group of another molecule. The glycosidic bond is broken through a hydrolysis reaction in which water cleaves the bond, splitting the sugar molecule.

Answer 251

A

six-membered rings; cyclical structure of sugar

Answer 252

A

five-membered rings; cyclical structure of sugar (more common form)

Answer 253

A

used to identify the presence of aldehydes and hydroxy ketones, and uses the oxidizing agent [Ag(NH3)2]+ to oxidize aldehydes to carboxylic acids. Ketoses can undergo tautomerization via an enediol intermediate to their aldose form, resulting in a positive Tollens test and the formation of a silver mirror appearance.

Answer 254

A

a technique used to determine the functional groups present in a sample; the data collected are plotted as percent transmittance vs. wavenumber. The signals in the spectrum correspond to bond-stretching vibrations and rotations at a certain frequency, and the signal intensity is dependent on the amount of energy absorbed.

Answer 255

A

ending for aldehyde = al
ending for ketone = one

Answer 256

A

composed of three fatty acyl groups bonded to glycerol through ester linkages.

Answer 257

A

A reaction at a low temperature (−78 °C) with a bulky base, such as (LDA), favors formation of the kinetic over the thermodynamic enolate because it requires a low activation energy to form.
The kinetic product is a result of deprotonation of the less substituted α-carbon (ie, contains more hydrogen substituents and is sterically more accessible to a bulky base).
- kinetic forms faster but is less stable (forms less substituted alkene)

A reaction at a higher temperature with a smaller base such as (NaH) would lead to deprotonation of the more substituted α-carbon and formation of the thermodynamic enolate (ie, enolate C=C double bond more stabilized by substituents) and therefore formation of the thermodynamic product.
- thermodynamic forms slower but is most stable because it forms the most substituted alkene

Answer 258

A

A common protecting group used for aldehydes; characterized by two –OR groups in place of the carbonyl.

Answer 259

A

originating from aldehydes and ketones, respectively, each contain one –OR group and one –OH group.

Answer 260

A

chrial molecules

enantiomers rotate them in opposite directions

Answer 261

A

ΔH is negative when heat is released
- the temperature of the system and its immediate surroundings increase– think about a piece of wood burning and heating up surroundings

ΔH is positive when heat is gained
- the temperature of the system and its immediate surroundings decreases.

Answer 262

A

will continue to vaporize to gas

It must gain an amount of heat equal to its heat of vaporization before all the liquid turns to gas and the temperature increases.

Answer 263

A

Isothermal processes, in which the temperature of the system does not change.

Adiabatic processes, which occur with no heat exchange between the system and the environment.

Isochoric (isovolumetric) processes, in which the volume of the system does not change.

Isobaric processes, in which the pressure of the system does not change.

Answer 264

A

Conduction is the transfer of heat through direct physical contact.

Convection is the transfer of heat through the flow of fluids. Fluids absorb heat from hotter regions and deliver it to colder regions.

Radiation is the transfer of heat through electromagnetic radiation, such as infrared light. Radiation heat transfer is significant only for high temperatures.

Answer 265

A

C = mc = q/ΔT

C= heat capacity
c= specific heat

Answer 266

A

coulomb
e= 1.6 x 10^-19 C

Answer 267

A

do not easily distribute charge

molecules tend to be closely linked with nuclei; most nonmetals are insulators; serve as dielectric materials for capacitors and prevent grounding

Answer 268

A

removal of a charge by transferring electrons between it and another object

Answer 269

A

distribute charge approximately evenly across surface; used in circuits and electrochemical cells; generally metals and ionic solutions

Answer 270

A

Quantifies the magnitude of electrostatic force between two charges: Fc=kq1q2 / r^2

k is Coloumb’s constant = 8.99 x 10^9 Nm^2 / C^2

Answer 271

A

E= Fe / q = kQ / r^2

Fe= electrostatic force
Q = source charge
q = test charge

Answer 272

A

field is stronger where lines are closer together

Answer 273

A

defined as the amount of work necessary to move a test charge from infinity to a point in space in an electric field

U=kQq/r

Answer 274

A

the ratio between the charge’s electrical potential energy and the magnitude of the charge itself

gives you potential of field without test charge

V= U/q = KQ/r

Answer 275

A

potential difference between two points at a different distance within the same magnetic field

∆V=Vb-Va=Wab / q

Wab is the work needed to move a test charge

Answer 276

A

A line on which the potential at every point is the same. So the potential difference between any two points is zero.

Answer 277

A

Results from two equal and opposite charges being separated by a small distance, d from each other. These can be transient (London dispersion) or permanent.

Answer 278

A

Any moving charge creates a magnetic field

the units for this strength are in Tesla [1 T = 1 N∙s/mC]

small magnetic fields are measured in gauss [1 T=10^4 gauss]

Answer 279

A

made of atoms with no unpaired electrons and have no net magnetic field.

These are slightly repelled by magnets (weakly antimagnetic).

E.g – wood, plastic, water, glass, skin

Answer 280

A

Do have unpaired electrons so that they do generate a net magnetic dipole moment.

Will become very weakly magnetized in the presence of an external magnetic field. This magnetic behavior is only temporary (only occurs while in presence of magnetic field).

E.g – aluminum, copper and gold

Answer 281

A

have unpaired electrons and permanent atomic magnetic dipoles. Oriented randomly so that the material has no net magnetic dipole naturally.

Will become strongly magnetized when exposed to a magnetic field or at certain temperature. E.g – iron, nickel, cobalt, bar magnets.

Answer 282

A

B=u0 x I / 2π x r

u0=permeability of free space=4π x 10-7 T∙mA

Answer 283

A

B=u0 x I / 2 x r

Answer 284

A

the sum of the electrostatic and magnetic forces.

Answer 285

A

FB=qvB sinΘ

v is the velocity, B is the magnitude of the magnetic field and is the smallest angle between the velocity vector and B.

Answer 286

A

For a straight wire: : FB=ILB sinΘ

I is the current, L is the length of the wire and B is the magnitude of the magnetic field, and is the angle between L & B.

Answer 287

A

used to model fluid flow in pipes, assuming laminar flow of viscous and incompressible fluids. According to Poiseuille’s law, the flow rate is directly proportional to vessel radius and pressure difference, and inversely proportional to viscosity and vessel length.

Answer 288

A

length L and radius r in meters (m)
pressure change ∆P in pascals (Pa)
volumetric flow rate Q in cubic meters per second (m^3/s).

Answer 289

A

For resistors connected in parallel, the voltage drop across each resistor is the same and the equivalent resistance increases if a resistor is removed.

The current through each resistor in parallel is independent of the others, and the sum of each component current equals the total current.

Answer 290

A

an intrinsic property of materials and varies with changes in the material’s temperature. (temp up, resistivity up)

Answer 291

A

If waves are in-phase, the displacements always add together. Resultant amplitude will be 2x the original amplitudes.

happens when two waves overlap in such a way that they combine to create a larger wave.

Vs Destructive interference happens when two waves overlap in such a way that they cancel each other out.

Answer 292

A

Two out of phase waves cancelling each other out completely.

Answer 293

A

used to compare two waves- whether they start at the same time or not

If completely out of phase, expressed as a difference of 2 or 180 degrees.

For circular polarization, only a 90° phase difference is required because only a 90° phase shift yields both the positive and negative oscillations along each axis and the symmetry necessary to produce a circular polarization pathway.

Answer 294

A

the component mass divided by the total mass of the formula unit or mixture expressed as a percentage. The total mass of a solution mixture equals the combined mass of solute and the solvent!

Answer 295

A

Yes, H–F bond is highly polar, and the fluorine atom has three pairs of nonbonding electrons.

H bonds are likely to form with N, O, and F to form noncovalent dipole-dipole attractions known as hydrogen bonding.

Answer 296

A

They are stronger.

A double bond will be stronger than a single bond though because it is a combination of a pi and sigma bond

Answer 297

A

noncovalent interactions are weak attractions between atoms that do not share electrons but have dipoles with opposite partial charges.
Noncovalent dipole interactions include attractions between two permanent dipoles, between a permanent dipole and induced dipole, and between two induced dipoles.

Answer 298

A

the weakest of the noncovalent van der Waals forces. These interactions occur between two atoms or molecules that are close to each other, creating a temporary dipole

London dispersion forces tend to be more pronounced in larger molecules with larger, more polarizable electron clouds (more branched nonpolar molecules)

Answer 299

A

the coordination number of a complex ion is the number of coordinate bonds to the central atom

Answer 300

A

the ratio of the actual yield (the amount obtained) to the theoretical yield (the amount possible) expressed as a percentage.

Answer 301

A

HIGHER in free energy than thermodynamic products and can form at lower temperatures. “Fast” products because they can form more quickly under such conditions.

Answer 302

A

LOWER in free energy than kinetic products, more stable. Slower but more spontaneous (more negative DG)

Answer 303

A

direction of particle oscillation is perpendicular to the propagation of the wave. Think above moving a string with a fixed point by moving hand up and down.

Includes electromagnetic waves like visible light, microwaves and x-rays.

appear as waves along path

Answer 304

A

particles of wave oscillate parallel to the direction of transfer

Sound waves, causes air particles to oscillate through cycles of compression and rarefaction (decompression) along the direction of the wave.

appear as lines along path

Answer 305

A

ω=2 π f=2π / T

Answer 306

A

v= (rad (B/p))

B is the bulk modulus increases from gas to solid
p is the density

fastest in solids, slowest in gasses

Answer 307

A

Describes the differences between the actual frequency of a sound and the perceived frequency of a sound.

If the source and the detector are moving towards each other, then the frequency is perceived to be higher. when source and detecter moving away, perceived to be lower.

Answer 308

A

I=PA

P is the power & A is the Area
(Area = A=4π r^2)
Intensity is proportional to the square of amplitude (A^2)

Intensity is inversely proportional to the square of the distance from the source (1/d^2)

Answer 309

A

If intensity is changed by some factor, can use: Bf = Bi+10 log If / Ii

Answer 310

A

light goes in a straight line when it is a homogenous medium

Answer 311

A

Θi = Θr

the perpendicular line in between them is called the normal

Answer 312

A

converges where the image appears; can be projected to a screen

Formed when rays of light are directed out of a fixed point

Answer 313

A

converges somewhere else, looks like it’s somewhere it’s not
Occurs one reason only appear to diverge

Answer 314

A

half the radius of curvature and is positioned in front of the mirror.

focal length = radius of curvature / 2

Answer 315

A

center of curvature C
radius of curvature r

focal length = radius of curvature / 2

inside of curve is concave (converges); outside of curve is convex (diverges)

Equation
(1/f) = (1/o) + (1/i) = (2/r)
o= object ; i = image ; r = radius
object distance (o) will always be positive because we think of things in terms of the object
if image is a real image i>o
if image is a virtual image i<o

Answer 316

A

m = i / o

if positive, image is upright

if negative, image is inverted

Answer 317

A

positive i = in front
negative i = behind

positive r= concave (converging)
negative r= convex (diverging)

positive f= concave
negative f= convex

positive m= upright
negative m= inverted

Answer 318

A

Applies to refracted rays of light

n1sinΘ1 =n2sinΘ2

if n1<n2>n2 will bend away from normal</n2>

Answer 319

A

in the context of acids, refers to the number of moles of protons per liter of solution
(Molarity x #protons)

Answer 320

A

when light goes to different medium and changes speed & bends

n = c / v

Answer 321

A

real and virtual images are opposite to mirrors
sign for concave lens will be negative (diverging)
sign for convex lens will be positive (converging)

Answer 322

A

a diverging (concave) lens because rays are converging too soon before retina

Answer 323

A

a converging (convex) lens because rays are converging too far away from retina

Answer 324

A

P = 1 / f
f is focal length

Answer 325

A

asinΘ= nλ

a= slit width
n = fringe number

dark bands that result from light passing through a diffraction grate are caused by destructive interference between light waves. Conversely, Light bands are caused by constructive interference between light waves.

Answer 326

A

dsinΘ= (n+(1/2)λ)

d = distance between slits
n = fringe number (all the peaks, largest one in the middle)

dark bands that result from light passing through a diffraction grate are caused by destructive interference between light waves. Light bands are caused by constructive interference between light waves.

Answer 327

A

linearly polarized light indicates presence of chiral center

Answer 328

A

Determines the amount of product formed in a reaction. This constant is not changed by a catalyst, which only changes the rate at which equilibrium is achieved.

Answer 329

A

says that the pressure of a gas is inversely proportional to the volume it occupies.

Answer 330

A

states that the amount of a gas that dissolves in a liquid is proportional to the partial pressure of that gas.

Answer 331

A

states that the rate of a reaction is proportional to the molar amount of each reaction component raised to the power of its reaction order. The reaction order of each species is equal to its stoichiometric coefficient.

Answer 332

A

light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light

Differences in the thickness of a thin film (top media) contribute to changed interference patterns that produce the colorful array.

Answer 333

A

indicates that at constant temperature and pressure, the number of moles of a gas within a container is directly proportional to the volume of the gas.

ex. if

(v1/n1) = (v2/n2)

Answer 334

A

the total pressure of a mixture of gases is equal to the sum of the partial pressure of each of the individual gases. The partial pressure of an individual gas can be found using the mole fraction of the gas multiplied by the total pressure.

Answer 335

A

Because only ELECTROMAGNETIC radiation with an electric field oriented parallel to the axis of polarization passes through, the total intensity of light will therefore decrease by 50% when nonpolarized light passes through a linear polarization filter.

Answer 336

A

multiply M1 x M2

Answer 337

A

will always be equal to the speed of light when in a vacuum

Answer 338

A

equals the ratio of the speed of light in a vacuum to the speed of light in the material.

n = c / v

n = refractive index
c = speed of light in vacuum
v = speed of light in material

Answer 339

A

indicate the direction and relative strength of E.

Begin at positive charges and end at negative charges (they point away from regions of higher voltages and toward regions of lower voltages) POS TO NEG and BIG TO SMALL VOLTAGE

E induces positive charges to move in the same direction as the field lines and induces negative charges to move in the opposite direction.

Answer 340

A

equal to the product of the wavelength and frequency of the sound waves. When sound travels through different mediums, its speed and wavelength may change, but the frequency remains constant.

Answer 341

A

λ=4L / n

n = harmonic number; must be odd when the harmonic series of a pipe is closed at one end because the closed end of a pipe is always a node and the open end is always an antinode.

Answer 342

A

states that the average molecular kinetic energy of an ideal gas is proportional to the product of Boltzmann’s constant kB and the temperature TK in Kelvin according to the equation KE = ((3/2)kB) x TK

Answer 343

A

refers to passage of light through an array consisting of numerous slits. Diffraction grating may be used to determine the components of polychromatic (eg, white) light and other mixed electromagnetic wavefronts.

Answer 344

A

half the radius of curvature and is positioned in front of the mirror.

Answer 345

A

Carbocations are strong electrophiles and a common intermediate in SN1 and E1 reactions. Nearby alkyl groups will stabilize them because they are electron donating
Carbocation: tertiary > secondary > primary > methyl

Carbanions act as strong nucleophiles due to the lone pair of electrons on the charged carbon. Nearby alkyl groups will destabilize them because they are electron donating.
Carbanion: methyl > primary > secondary > tertiary

Answer 346

A

Eclipsed bonds generate torsional energy due to the steric repulsion of electrons between the aligned groups. Larger alkyl groups generate greater torsional energy for eclipsed bonds.

Staggered conformations have Newman projection groups oriented at 60° intervals and are lower energy than eclipsed conformations.

Alkyl groups with a θ = 60° (a gauche conformation) exhibit modest torsional energy.

the anti conformation (when methyl is far from other functional group, limiting electron- electron repulsion) is the most stable – want groups to be as far apart as possible

Answer 347

A

having more alkyl attachments (tertiary)
these are favored in SN1

Answer 348

A

as the electronegativity of a negatively charged atom decreases from right to left across a period on the periodic table, its nucleophilicity increases–

less electronegative atoms stabilize a negative charge less effectively, have a weaker hold on electrons, and more readily donate electrons to an electrophile.

Answer 349

A

electron withdrawing groups destabilize
electron donating groups stabilize

Carbocations are stabilized by electron donating groups because they donate electrons to the positively charged carbon; they are destabilized by electron withdrawing groups because they pull electrons away from the carbocation, creating two adjacent positive charges.

Answer 350

A

is decreased when a molecule is more branched

Answer 351

A

is decreased when a molecule is more branched

Answer 352

A

CD spectra is the difference in absorption between left and right handed circularly polarized light

absorption differs because of chirality– will be negative when Aright > A left and positive when Aleft > A right

Answer 353

A

when an pi electrons grabs an H to generate a carbocation

makes an even mixture of primary carbocation and secondary carbocations; the secondary will be more stable

Answer 354

A

as you add more electron withdrawing groups, will become more acidic

Answer 355

A

they are good leaving groups and will be used in reactions when you want to replace a poor leaving group

The hydroxyl O acts as the nucleophile to attack the S of TsCl, and Cl acts as the leaving group.

Answer 356

A

keto- enol tautomerization will typically favor keto, except for phenol due to resonance stabilization

Answer 357

A

cyclical esters

Answer 358

A

Acyl halide > anhydride (3 Os) > ester > amide
weakest base/ most stable leaving group to strongest base/least stable leaving group

Answer 359

A

a reaction that removes a carboxyl group from a carboxylic acid with a β-carbonyl, releasing the carboxyl group as CO2 gas.

A β-carbonyl (two carbons away from other carbonyl) is necessary for decarboxylation because a cyclic transition state incorporating both carbonyls is formed.

Answer 360

A

a CA derivative– contains two carbonyl groups linked together by an oxygen atom and is made by the condensation of two CAs

Answer 361

A

Esters are more reactive than amides due to a stronger electron-withdrawing, inductive effect caused by the greater electronegativity difference between the C and O atoms in esters compared to the C and N atoms in amides.

Dipole created by ester increases electrophilicity

The amide also can resonate, which makes it less electrophilic

Answer 362

A

proceed in two steps and involve the formation of a carbocation intermediate

Answer 363

A

the exchange of alcohol and alkoxy R groups between an ester and an alcohol.

break a C-O bond and form a new C-O bond

Answer 364

A

When carbon atoms are oxidized, they lose bonds to hydrogen and/or gain bonds to oxygen. Therefore, oxidizing agents convert primary alcohols to aldehydes and carboxylic acids, and secondary alcohols to ketones. However, tertiary carbon atoms have no bonds to hydrogen.

Answer 365

A

deprotonates the most substituted alpha carbon

Answer 366

A

Kinetic enolates are formed by deprotonation of the least substituted α-carbon of a carbonyl compound using a bulky base, such as LDA at low temperatures.

Thermodynamic enolates are formed by deprotonation of the more substituted α-carbon using a small base, such as NaH, at higher temperatures.

Answer 367

A

NaH at high temperature

Answer 368

A

LDA at low temperature

Answer 369

A

Add up both strength values (in diopeters)

Answer 370

A

helps regulate fatty acid metabolism by inhibiting long-chain fatty acid transport into the mitochondria. Processes that decrease malonyl-CoA levels are likely to increase fatty acid transport to the mitochondria and, as a result, increase beta oxidation.

Answer 371

A

material used for the synthesis of fatty acids

Answer 372

A

cornea and lens, both of which form a biological converging lens that focuses incoming light rays onto the retina, a structure analogous to the film or sensor within a camera.

Answer 373

A

farsightedness

a condition that results when the optical power (S) of the eye is insufficient to refract light rays from nearby objects. Cannot sufficiently refract light rays that approach the eye at an angle (eg, light rays from nearby objects), producing an image of nearby objects that is sharpest at a location behind the retina.

Answer 374

A

by placing a converging lens in front of the eye, forming an optical system with greater optical power.

Consequently, placing a corrective lens in front of the hyperopic eye shifts the focal length towards the eye’s lens and light from nearby objects is focused onto the retina.

Answer 375

A

nearsightedness

a visual condition in which the eye forms an image of distant objects at a focal point in front of the retina. Correcting myopia (not hyperopia) shifts the image away from the lens.

Answer 376

A

refers to the optical deficiencies of lenses with perfectly spherical surfaces.

Answer 377

A

This vibration creates oscillations of compressions (areas of high pressure) and rarefactions (areas of low pressure), resulting in a propagating pressure wave

Attenuation (damping) is the decrease in the amplitude (intensity) of a wave due to absorption and scattering. The magnitude of the attenuation depends on the properties of the medium; attenuation is greater for softer materials

The speed of sound is slowest in gases, faster in liquids, and fastest in solids. Because sound propagates through the vibrations of the molecules in a medium, sound cannot propagate through a vacuum.

Answer 378

A

The decibel (dB) scale is logarithmic and relates the perceived loudness of a sound to its actual intensity.

ex. For each 10-fold decrease, sound intensity decreases by 10 dB. Therefore, a 100-fold decrease in sound intensity corresponds to a decrease by 20 dB.

Answer 379

A

period (T) of a wave is the amount of time for one cycle (or one wavelength) to pass through a fixed point. Period is the reciprocal (inverse) of frequency:

T=1 / f

Answer 380

A

The fundamental frequency of standing sound waves in a tube of fixed length depends on whether the pipe is open at both ends or closed at one end.

pipe open on both ends will resonate at the fundamental frequency when antinodes are formed at each end. A pipe with one end open will resonate at the fundamental frequency when a node is formed at the closed end and an antinode is formed at the open end.

frequency when pipe is closed will be double the frequency of when the pipe is open (fo = 2fc)

Answer 381

A

number of nodes will tell you the harmonic (can’t count nodes for closed ends)

Answer 382

A

a portion of the wave’s energy is reflected. Therefore, sound waves lose energy (are attenuated) and their intensity decreases when passing from air to a solid structure, such as the tympanic membrane.

v = λf

frequency does not change.
Changes in wave velocity cause the wavelength to change:
- Velocity increases with temperature.
- Velocity is slowest in gases, faster in liquids, and fastest in solids.
- Within a phase of matter, velocity increases with stiffness and decreases with density.

Answer 383

A

The frequency of a sound is associated with its perceived pitch; high-frequency sounds have high pitches. The low-frequency sounds that cause resonance near the apex of the basilar membrane are characterized by low pitches.

Answer 384

A

L = λ / 2

Answer 385

A

Hydrogen bonding determines how far a mixture will migrate (stronger hydrogen bonding –> migrate more slowly)

solute concentration will affect the size of the spots

the thickness of the paper will affect the amount of each component that can be fully separated

Answer 386

A

distance traveled / distance to the solvent front

Answer 387

A

amide groups

Answer 388

A

The first peak will be the least polar and most volatile compound

a volatile compound will have weak attractions (likely to vaporize)

Answer 389

A

Stabilizing a negative charge by adding an electronegative atom

Diluting a solution (Le Chat)

Answer 390

A

Stabilizing a negative charge by adding an electronegative atom

Diluting a solution (Le Chat)

Adding a basic indicator (increases the amount of dissociated (ionized) acid)

To decrease ionization… could add HCl– as a strong acid, the amount of H+ will be increased and will therefore decrease the percentage of an acid that will ionize

Answer 391

A

energy of electromagnetic radiation is directly proportional to the number of photons

the intensity of electromagnetic radiation is defined as energy emitted per unit time

intensity is directly proportional to the number of photons emitted.

Answer 392

A

Intermolecular covalent bond; will make a compound more structurally rigid

Answer 393

A

Aspartic Acid (D)
carb acid 2 carbons away from amino group

Answer 394

A

Glutamic acid (E)
carb acid 3 carbons away from amino group

Answer 395

A

Asparagine (N)
has amide

Answer 396

A

the total cross sectional area of capillaries is larger (since there are more of them in the body); this decreases the velocity of blood

Answer 397

A

the increased ration of surface area to blood volume in the capillaries compared to arteries means that the blood contacts more blood vessel surface area; this slows down the velocity and drops the blood pressure

blood pressure is lower in capillaries than arteries

blood travels slower in capillaries than arteries

Answer 398

A

due to small diameter, capillaries have highest resistance (except for arterioles)

Answer 399

A

blood flow is inversely proportional to the total cross sectional area

Answer 400

A

The gas particles have negligible volume.

The gas particles are equally sized and do not have intermolecular forces (attraction or repulsion) with other gas particles.

The gas particles move randomly in agreement with Newton’s Laws of Motion.

The gas particles have perfect elastic collisions with no energy loss.

Answer 401

A

ATP hydrolysis hydrolyzes ATP
Protease cleaves peptide bonds
Lipase hydrolyzes triacylglycerides
Transferase transfers carboxyl groups

Answer 402

A

α-1,4-glycosidic bond

Answer 403

A

Glucose - is sweet like a milk DUD (carbon #234 is down up down)

Galactose - in this galaxy DUU you (Carbon #234 down up up)

For glycogen I need to know It’s alpha 1,4 bonds ( move 4RWARD) to keep the chain growing

And alpha 1,6 = put a branch in the mix (six = mix)

Fructose - is fudge (FUD) fructose ( up down for carbon number 2 and 3) -remember fructose is a furanose ring

Answer 404

A

compounds with negative charges will have decreased dissocation

Answer 405

A

1 / f = 1 / u + 1 / v

f= focal length
u= object distance
v= image distance

Answer 406

A

the ratio of the image height to the object height is equal to the ratio of the lens-image distance to the object-lens distance.

Answer 407

A

yes, they are okay as reducing agents

Answer 408

A

when E° is greater than 0

Answer 409

A

J / s = ft x lb / s = kg x m^2 / s ^3.

Answer 410

A

22.4 L / mol

Answer 411

A

Will decrease boiling point– Having fewer H bonds decreases the extent of hydrogen bonding and lowers the energy required to overcome the intermolecular attractions.

Answer 412

A

ΔG is the difference between products and reactants
Ea is the difference between the reactants and the top of the transition state

Answer 413

A

k=Ae^(−Ea/RT)

(k = rate constant of the reaction; A = constant that represents the collision frequency and structural factors specific to the reactants; The exponential term e^((−Ea)/(RT)) corresponds to the fraction of collisions with enough kinetic energy to overcome the activation energy Ea at a given temperature T. R is the gas constant (8.314 J∙mol^−1∙K^−1).)

The collision theory of kinetics assumes that molecules must collide for a reaction to occur. The collisions must have enough kinetic energy to overcome the activation energy. Arrhenius equation describes this concept mathematically.

Answer 414

A

Buffers consist of a mixture of either a weak acid and a salt of its conjugate base, or a weak base and a salt of its conjugate acid.

ex. CH3COOH(weak acid) and CH3COONa (Na acts as salt)

Answer 415

A

Remember a BL base is a hydrogen acceptor

HNO3

molecule that is accepting! not the one that accepted

Answer 416

A

oxidation occurs at the anode

reduction occurs at the cathode

electrons flow from the anode to the cathode.

Answer 417

A

A large Ka and a small pKa will indicate a strong acid

pKa = -log Ka

Answer 418

A

the angle of reflection is always equal to the angle of incidence, irrespective of the refractive index on either side of the media interface

θi=θr

Answer 419

A

Inertia refers to the ability of an object in motion to stay in motion and an object at rest to stay at rest. An object’s inertia depends on its mass and is also proportional to the maximum static friction force it experiences when stationary. Therefore, a stationary object with a large inertia could remain stationary when another smaller object strikes it.

Answer 420

A

occurs when the net external force acting on an object is equal to zero. This does not imply that no forces are acting on the object, but rather that all forces acting on the object are balanced

two forms: Static equilibrium occurs when the object has zero velocity, and dynamic equilibrium occurs when the object has a constant nonzero velocity.

Answer 421

A

states that work W done by a force on an object can be calculated as the change in the object’s kinetic energy ΔKE.

Answer 422

A

mechanical waves that propagate at a frequency above the upper bound of the human auditory spectrum (~20 kHz).

One example is shock wave therapies which use high frequency waves to cause destructive, high amplitude vibrations; to be most effective, frequency of the shock waves should match the resonance frequency of the target structure

Answer 423

A

T = r x F

When in static rotational equilibrium, there is no net rotational movement, and the sum of all torques is zero.

Answer 424

A

P = F / A

Answer 425

A

kg / m⋅s^2 is equivalent to N / m^2

Answer 426

A

the ratio of the output force Fo to the input force Fi and. due to the conservation of energy, also equal to the ratio of distances

Fo / Fi = di / do

where di and do are the distances from the pivot point to the input and output forces

Answer 427

A

The cosine function takes the parallel component of a vector, and its magnitude is lowest at 90

Answer 428

A

The sine function takes the perpendicular component of a vector, and its magnitude is greatest when θ is 90°

Answer 429

A

the total energy (U) of an object is quantified by the sum of kinetic energy (KE) and potential energy (PE):

U=KE+PE

Conservation of energy requires that an object’s total energy observed between two points (A and B) remains the same, but contributions from potential energy may convert to kinetic energy (or vice versa) within mechanical systems:

1/2 mvA^2 + mghA=1/2 mvB^2 + mghB

Answer 430

A

potential energy measures the potential of conservative forces to do work, the change in potential energy (ΔU) relative to this point is equal and opposite to the work (W) done by conservative forces within the system

Answer 431

A

The kinetic energy would be converted into potential energy

Answer 432

A

hotter; because of the high energy

Objects with high energy have a higher temperature and emit EM waves with relatively higher frequencies and energy.

Answer 433

A

circuits exhibit conservation of energy around a closed path (loop) in the circuit, in which the direction of the path matches the direction of the current in the loop. As a result, Kirchhoff’s loop rule states that the sum of the voltage drops V around any closed loop in a circuit equals zero:

∑i=1nVi=V1+V2+⋯Vn=0

Answer 434

A

Unknown currents in different branches of a circuit can be found by applying the junction rule, which states that total current entering a junction must equal the total current exiting the junction.

Ohm’s law and the loop rule (the sum of all the electric potential differences around a loop is zero) are used to determine voltage and resistor values.

Answer 435

A

Fc=mv^2 / r

n uniform circular motion the instantaneous velocity vector is always tangent to the circular path. The inertia of the object wants it to continue going straight, but this is stopped by the centripetal force, which is always pointed radially inwards.

Answer 436

A

lower

n = c / v

Answer 437

A

As a wave propagates, it carries energy from one location to another. The energy contained in a wave is directly proportional to the square of its amplitude but is independent of the wavelength and frequency.

When a wave moves from one medium to another, the amplitude and wavelength change but the frequency of the wave remains constant.

Answer 438

A

no - Wavelength and amplitude depend on the type of medium, but frequency is independent of the medium.

Answer 439

A

For a floating object, the fraction submerged is equal to the ratio of the object’s density to the fluid’s density:

fraction submerged= ρobject / ρfluid

Answer 440

A

The current entering and exiting a resistor remains the same because electric charge is always conserved.

Answer 441

A

According to Archimedes principle, a submerged object experiences an upward buoyant force FB due to the displaced fluid. Therefore, an object will appear to weigh less than its in-air weight Wair when submerged in water, given by the object’s apparent weight Wapparent:

FB=Wair−Wapparent

buoyant force experienced by the individual is equal to the weight of the displaced fluid, which is the product of the density of water ρ, the displaced volume V, and the gravitational acceleration g:

FB=ρVg

Answer 442

A

the ratio of its density to the density of water:

specific gravity=ρsubstance / ρwater

Answer 443

A

for an object fully immersed in two different fluids (1 and 2), the ratio of buoyant forces is equal to the ratio of fluid densities:

FB,1 / FB,2 = ρ1V1g / ρ2V2g = ρ1 / ρ2

Answer 444

A

the pressure exerted by the weight of a static (nonmoving) fluid.

The magnitude of P is the product of the fluid density ρ, the gravitational acceleration g, and the height h of the fluid above the point of interest:

P=ρgh

Answer 445

A

μk= FA / mg

Answer 446

A

If the object is sliding with constant velocity on a flat surface, the coefficient of kinetic friction is calculated from the force applied to the object and the mass of the object.

Answer 447

A

cardiac output is the volume of blood the heart pumps in 1 minute. It is calculated by multiplying the stroke volume of the heart and the heart rate.

Answer 448

A

average kinetic energy

Answer 449

A

Ideal fluids are totally nonviscous and incompressible; they exhibit smooth, laminar flow without viscosity. Bernoulli’s equation dictates that an increase in the velocity of an ideal fluid is accompanied by a decrease in fluid pressure.

Answer 450

A

normal force

Answer 451

A

The kinetic friction force between two surfaces is proportional to the normal force exerted by the surfaces. For an object on a ramp, the normal force is equal to the perpendicular component of object’s weight, which decreases as the angle of inclination increases.

Answer 452

A

Vx= V⋅cos θ

Vy= V⋅sin θ

Answer 453

A

When a battery is charging, it functions as an electrolytic cell because an external potential drives the oxidation-reduction reaction to proceed in a nonspontaneous direction (ie, ΔG > 0; Ecell < 0).

When charging a battery, an external positive electric potential must be applied to force the spontaneous (ΔG < 0) oxidation-reduction reaction in the nonspontaneous (ΔG > 0) direction. The net ΔG for the system must be negative to charge the battery.

Answer 454

A

In either case, oxidation occurs at the anode and reduction occurs at the cathode, and electrons flow from the anode to the cathode.

Answer 455

A

When a battery is discharging, it behaves as a galvanic cell; when it is charging, it behaves as an electrolytic cell.

Answer 456

A

The equilibrium constant Keq expresses the relationship between products and reactants at equilibrium. When temperature increases, Keq decreases for exothermic (ΔH° < 0) reactions and increases for endothermic (ΔH° > 0) reactions.

Answer 457

A

As a polar compound, water is an efficient solvent due to its ability to interact with other polar or charged compounds.
The polar nature of water is due to the difference in the electronegativities of oxygen and hydrogen, along with a bent geometry.
The small size of the water molecule allows efficient interactions with solutes, forming a hydration shell around and dissolving them.

Answer 458

A

intermolecular forces between molecules.

These interactions are affected by the presence of solutes. As a colligative property, the extent of freezing point depression of a solution is a function of the amount of solute added.

Answer 459

A

According to Raoult’s law, the vapor pressure of a liquid decreases (dashed line) at any given temperature when solute is added. Briny water will therefore need to be heated to a higher temperature for its vapor pressure to reach the same ambient pressure and begin to boil. Therefore, the boiling temperature (boiling point) of briny water is higher than that of pure water under the same atmospheric conditions.

Answer 460

A

I = 1 / r^2

intensity is inversely proportional to squared distance

Answer 461

A

ERadio waves < EMicrowaves < EInfrared light < EVisible light < EUltraviolet light < EX-rays < EGamma rays

Answer 462

A

Yes, X-ray diffraction through a sample of a purified and crystallized material can be used to determine its three-dimensional molecular structure and packing

Answer 463

A

the medium it travels in (specifically the medium’s temperature, elasticity, and density)

Answer 464

A

λn=2L / n

Answer 465

A

λn=2L / n

Answer 466

A

Amplitude

Mechanical waves with a higher amplitude carry greater energy than waves with a lower amplitude.

Answer 467

A

occurs when lenses with perfectly rounded surfaces focus light at multiple focal points. Spherical aberration is most pronounced among light rays entering and exiting the periphery of converging lenses.

Answer 468

A

occurs when lenses with perfectly rounded surfaces focus light at multiple focal points. Spherical aberration is most pronounced among light rays entering and exiting the periphery of converging lenses.

Answer 469

A

involve the displacement of one group for another on a carbonyl carbon.

Answer 470

A

Substitution reactions involve the displacement of one group by another.
Addition reactions involve two groups adding across a pi bond, consuming the pi bond in the process.
Elimination reactions involve the loss of two groups from adjacent carbon atoms and the formation of a new pi bond.

Answer 471

A

Steric effects - size or proximity of functional groups near a reaction center, where larger groups tend to decrease the rate of reaction.

Electronic effects - molecular features involving electron density, including polarity, resonance, or conjugation. The major players in electronic effects are lone pairs or pi bonds.

Answer 472

A

A soap is a sodium carboxylate salt of a fatty acid.

Soaps can be produced through basic hydrolysis of fatty acyl–containing lipids like triacylglycerols or phospholipids. The number of unique soap molecules that can be generated is dependent on the number of unique fatty acyl groups (hydrocarbon tail connected to carbonyl) in the source lipid.

Answer 473

A

NP-HPLC consists of a polar stationary phase and a nonpolar mobile phase (non polar elutes faster)

RP-HPLC consists of a nonpolar stationary phase and a polar mobile phase. Molecules with polarity similar to the stationary phase interact with it more and have longer retention times. (nonpolar retained longer, polar elutes faster)

Answer 474

A

Molecules with UV chromophores (double and triple bonds, carbonyls, conjugated systems)

p.s. UV excites electrons into a higher energy state

Answer 475

A

yes, must heat slowly so they can be separated by boiling points

Answer 476

A

First, determine which of the reactants is rate limiting by calculating the moles of both reactants (use mol ratios), then convert to grams to get theoretical yeild

Answer 477

A

If two systems are in thermal equilibrium, and one is in thermal equilibrium with a third system, all three systems will be in equilibrium

Answer 478

A

Static Friction = Normal Force x Static Friction coefficient.

Uk = Fs / FN

Answer 479

A

On a sliding ramp: FN=FWcosθ

FN= mg

Kinetic friction = Uk x FN = Fwsinθ

Answer 480

A

Zeff = Z – S
Z = nuclear charge
S = core electrons

The core electrons partially shield the valence electrons, decreasing the nuclear charge

Answer 481

A

In aqueous solutions, strong acids ionize essentially 100%, giving large values of Ka and high [H+].

Weak acids ionize only to a small extent, giving small values of Ka and [H+] that are much lower than the concentration of the non-ionized acid.

Answer 482

A

Alkali metals

Answer 483

A

Alkaline earth metals

highly reactive family of metals with only two valence electrons that are readily lost to form cations with an oxidation state of +2. Alkaline-earth metals react with water to form hydrogen gas and either a basic hydroxide or an oxide, and the reactivity increases with increasing atomic number.

Answer 484

A

It is a 1:1 ratio; Faraday’s constant is 9x10^4

Answer 485

A

the total number of electrons released from the oxidation half-reaction must equal the total number of electrons used by the reduction half-reaction.

Answer 486

A

hydrolysis requires water
dehydration loses a water molecule

Answer 487

A

Imines are formed from a ketone or aldehyde and NH3 or a primary amine via an acid-catalyzed addition of the amine followed by an acid-catalyzed dehydration.

Answer 488

A

when weak acids are added to a mixture.

Answer 489

A

Amines are weak bases that require strong acids to be protonated.
Phenols are weak acids that are only deprotonated by strong bases.

Answer 490

A

mass number - protons (atomic number)

Answer 491

A

Elements with a lower first ionization energy are easier to ionize and more reactive than elements with a higher ionization energy.

(Ionization energy has the same trend as electronegativity)

Answer 492

A

electrons move around the nucleus in fixed circular orbits at particular intervals.

Electrons in orbits farther from the nucleus have higher energy!

Energy equal to the difference between two orbits is absorbed by an electron moving to a higher orbit and is emitted by an electron moving to a lower orbit.

Answer 493

A

If [X]^c[Y]^d < Ksp, the solution has not reached the solubility limit and will permit more ions into solution (dissolution).

if [X]^c[Y]^d > Ksp, the solubility limit of the solution has been exceeded and the solution will not accept any more ions (precipitation). This will cause any ions in excess of the Ksp to come out of solution as a precipitate!

Answer 494

A

relates k value and conc of reactants

Answer 495

A

An exothermic reaction (-ΔH°) releases heat. increasing the temperature causes the reaction to shift toward the reactants (ie, Keq decreases) to compensate for the heat gain in accordance with Le Châtelier’s principle.

An endothermic reaction (+ΔH°) absorbs heat. increasing the temperature causes the reaction to shift toward products (ie, Keq increases).

Answer 496

A

PV=nRT

where P is the pressure, V is the volume occupied, n is the number of moles, T is the absolute temperature (in Kelvin!!!!!), and R is a constant.

Answer 497

A

The power dissipated in a circuit is the product of current and voltage. (P=IR) In a parallel circuit, the branch with the lowest resistance has the largest current and the largest power dissipation.

Answer 498

A

no- sound waves are mechanical and require a medium;

Answer 499

A

no- sound waves are mechanical and require a medium;

Answer 500

A

Will impact the molecules that are able to become protonated/deprotonated and therefore decrease the amount of these molecules in solution

Answer 501

A

If the Ksp is small, then small changes to [A2+] or [X−] have a much larger impact than would be the case if the Ksp were large.

Answer 502

A

The relative speed between two objects depends on their directions of motion. The minimum relative speed occurs when two objects move in the same direction, and the maximum relative speed occurs when two objects move in opposite directions.

Answer 503

A

buoyant force experienced by an object floating at the surface is equal to the weight of the object

Answer 504

A

is the bending of light around physical corners or very narrow gaps

Answer 505

A

the spreading of light into its different frequencies (colors) due to differences in the index of refraction for different frequencies of light.

Answer 506

A

aligns transverse electromagnetic radiation along a specific orientation, such as vertical, horizontal, etc.

Answer 507

A

1.6 x 10^-19

Answer 508

A

Steroids are classified as nonhydrolyzable lipids because they do not contain any hydrolyzable ester or amide linkages.

Answer 509

A

two carbonyls (H bond acceptors) will elute furthest; weakest interactions with stationary phase and fastest migration

one hydroxyl group (H bond donor + acceptor) and one carbonyl will elute the second fastest

two hydroxyl groups (H bond donor + acceptor) have strongest interactions and slowest migration

Answer 510

A

two carbonyls (H bond acceptors) will elute furthest; weakest interactions with stationary phase and fastest migration

one hydroxyl group (H bond donor + acceptor) and one carbonyl will elute the second fastest

two hydroxyl groups (H bond donor + acceptor) have strongest interactions and slowest migration

Answer 511

A

made up of a nonpolar hydrocarbon chain with a polar carboxyl head group, and can be classified as either saturated or unsaturated.

Answer 512

A

The surface tension of a liquid is a result of strong cohesive forces between its molecules. Surface tension creates a tendency to decrease exposed surface area due to a net inward force at the surface molecules.

Answer 513

A

Current flow is equal through all elements of a series circuit.

Answer 514

A

P = I V

the product of the current and voltage.

Answer 515

A

an intrinsic property of a fluid that characterizes the amount of friction resisting motion inside the fluid itself.

Answer 516

A

Occurs when a species absorbs high-frequency light and then returns to its ground state in multiple steps. Each step has less energy than the absorbed light and is within the visible range of the electromagnetic spectrum.

can occur when the absorbed radiation has a photon energy larger than the photon energy of the radiation emitted through fluorescence.

Answer 517

A

Yes- electric field lines are used to denote the direction that a positive charge would be accelerated in an electric field. (point toward negative)

Answer 518

A

represents a space that exerts a force on charged particles.

The magnitude of a uniform electric field E is the voltage difference V divided by the distance d of the field:

E=ΔV/d

Answer 519

A

transfer of heat from skin into environment

Answer 520

A

transfer of heat from tissues to skin

Answer 521

A

1.6 x 10^-19

Answer 522

A

y-axis representing ion abundance and the x-axis representing the mass-to-charge ratio (m/z).

remember, peaks represent ionized fragments

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