Chem/Phys Flashcards
If a number has a decimal, how many significant figures are there?
Ex. 34,600. and 01.10
All the numbers (besides leading zeroes) are significant
34,600. has 5
01.10 has 3
When dividing numbers with decimals, how do you round to estimate?
same direction- makes answer closest to actual
Simplify (a+b)^2
a^2+2ab+b^2
Simplify log(a^3)-log(a)
log(a^3)-log(a)
log a^3/a
log a^2 or 2loga
Estimate log 7,426,135,420
log 7,426,135,420
log 7.4 x 10^9
9+0.74
about 9.74
**logs are just like opposite of exponents, so get rid of 10s
What is a common way that inverse trigonomic functions are used?
calculate the direction of a resultant vector in vector addition and subtraction
when multiplying numbers, how do you determine sig figs?
the answer has the least number of sig figs based on numbers being multiplied
when adding numbers, how do you determine sig figs?
smallest number of decimal places based on numbers being added
What is the relationship between ln and log?
logx=lnx/2.303
2.303 is a constant
what are units of concentration?
Concentration=Molarity(M)=mol/L
What is the formula for calculating between Fahrenheit and Celsius?
F=9/5C+32
How do you calculate the equilibrium partial pressure (Kp)?
The molar ratio of products to reactants when equilibrium is achieved. ***Also, each reactant must be raised to the power of it’s stoichiometric coefficient in the equilibrium expression
ie
if there are 2 mols of reactant Kp= (product)/reactant^2
How does IR spectroscopy work and what does it detect
IR radiation causes bond stretching and bending vibrations at different frequencies, allowing for functional group identification.
Different functional groups absorb different amounts of light
On an IR spectrum, what are the noticeable characteristics of carboxylic acids
Broad O-H stretch (3300-2400)
Strong C=O stretch (1710)
what factors does the reactivity of carboxylic acid derivatives with a nucleophile depend on
inductive effects, steric effects, and leaving group stability
Is the net reaction the simplified or total equation?
total
What effect do dimers have on melting points?
increase melting point
What is the IUPAC name of this compound
What are two effects that cause reactions to favor one direction over the reverse reaction?
Electronic effects: such as polarity, resonance, and conjugation. tend to go in the direction of more electrophilic ->less electrophilic
steric effects: larger groups tend to decrease the rate of rxn (mostly stay in directions smaller->larger)
Does this work? If not, why?
No, because the condensation reaction between a carboxylic acid and amine is not spontaneous and typically requires additional earlier steps to activate the carboxylic acid of nucleophilic attack
What type of reaction is addition of LiAlH4 and what does it do to carboxylic acids?
strong reducing agent; carboxylic acids undergo a double hydride reduction to a primary alcohol
Does hydrogen bonding make something more or less polar?
MORE- carboxylic acids more polar than aldehydes
In thin-layer -chromatography, which substances will have higher Rfs?
less-polar substances have higher Rfs because polar ones interact more strongly with the stationary phase
When is it best to use fractional distillation instead of simple distillation?
When separating compounds with a boiling point difference of less than 25 C.
Cohort studies
look at a group divided by risk factors and follow over time to see the outcome
ie
100 smokers and 100 non-smokers followed for 20 years to see If they delevop cancer
cross-sectional studies
look at a group at a specific time and see if they have an outcome
ie look at 100 smokers and 100 non-smokers and see which ones at that moment have cancer
case-control studies
look at an outcome and trace back to see what risk factors
ie look at 100 people with lung cancer and 100 people without and see which of them smoked before
Which Hill’s criteria is NECESSARY for suggesting any causality? Is it enough?
Temporality: the independent variable (exposure) MUST occur before the dependent variable (outcome). Still not enough, more criteria strengthens causality, but cannot be definitively proven in observational studies
What is the difference between bias and confounding errors in a study?
Bias is an issue during the data collection phase, and confounding variables happen during data analysis when an association is drawn between two variables when in fact a confounding one cause them
ie. believe redheads have higher pain tolerance, but really it’s a gene mutation that causes both of them
What is the difference between bias and confounding errors in a study?
Bias is an issue during the data collection phase, and confounding variables happen during data analysis when an association is drawn between two variables when in fact a confounding one cause them
ie. believing redheads have higher pain tolerance, but really it’s a gene mutation that causes both of them
What is the difference between internal and external validity
internal validity: the tendency of the same experiment to produce the same result when repeated
external validity: ability to apply it to the larger population aka generalizability
Enzymes _____ activation energy
lower
Enzymes ____ the overall delta G
do not affect
What do oxidoreductases do?
What are three enzyme namings to look out for?
catalyze oxidation-reduction reactions (often with an electron-carrying cofactor such as NAD+ and NADP+)
names:
dehydrogenase
reductase
oxidase (normally oxygen is final acceptor)
What are transferases? What is a subcategory of this group and what do they do?
Catalyze the movement of one functional group to another
Subcategory: kinases that catalyze the transfer of a phosphate group (normally from ATP) to another molecule
What do hydrolases do? How are lyases different?
Catalyze the breaking of a compound into two molecules with the addition of water. Lyases break a single molecule into two parts WITHOUT using water (lyases can also catalyze two substrates into one product)
What do isomerases do?
catalyze the rearrangement of bonds within a molecule
What do ligases do? How do they normally differentiate from lyases?
Ligases catalyze addition or synthesis rxns between large similar molecules. Lyases generally are with smaller molecules
Prosthetic group definition
Tightly bound cofactor or coenzyme necessary for enzyme function
Enzymes with their cofactors are called_____ while ones without their cofactors are called____
holoenzymes (WHOLE)
apoenzymes (without)
how do cofactors normally differ from coenzymes
cofactors tend to be inorganic (minerals) and coenzyme tend to be small organic compounds (vitamins)
How will increasing [S] and [E] affect enzyme activity in terms of vmax?
[S] will increase reaction kinetics up until Vmax is reached at which case adding more does not increase reaction speed
[E] increases will always increase vmax
What is Km?
Km is a measure of an enzyme’s affinity for its substrate or [S] at which an enzyme is functioning at half of its maximal velocity.
As Km increases…
An enzymes affinity for its substrate decreases
What is the x-intercept on the line-weaver burke plot?
x-intercept: -1/km
What is y-intercept on line-weaver burke plot
y-intercept: 1/vmax
If Hill’s coefficient is greater than 1 there is _____
positive cooperativity
If Hill’s coefficient < 1
negative cooperativity
What effect does temp have on enzymes
Increase, until above body temperature, than decrease and denature
What effect does salinity changes have on enzyme function
changes in salinity disrupt bonds in an enzyme disrupting tertiary and quaternary structure
What temperature (C F and K) do enzymes in the body perform best at?
37C=98.6 F=310K
Ideal pH for most enzymes?
gastric enzymes?
pancreatic enzymes?
Ideal pH for most enzymes: 7.4
Ideal pH for gastric enzymes: ~2
Ideal pH for pancreatic enzymes: ~8.5
Compare and contrast competitive inhibition, noncompetitive inhibition, mixed inhibition, and uncompetitive inhibition
In a neutral solution, most amino acids exist as _______ and AAs with uncharged R-groups have an overall ______ charge
zwitterions; 0
What force stabilizes the alpha-helices helix?
hydrogen bonds between a carbonyl oxygen and amide hydrogen 4 down
what two factors denature proteins
solutes and heat
A particular alpha-helix is known to cross the cell membrane. What amino acid is most likely to be found in the transmembrane portion of the helix?
a. phenylalanine
b.glutamate
c.lysine
d. glutamic acid
a. phenylalanine
Length SI units
meters (m)
mass SI unit
kg
time SI unit
seconds (s)
current SI unit
ampere (coulomb/second) A
amount of substance SI unit
mol
temperature SI unit
K
luminous intensity SI unit
candela (cd)
derived units for Newton from SI
(kg*m)/s^2
derived units joule from SI
(kg*m^2)/(s^2)
derived units for watt from SI
(kg*m^2)/(s^3)
When calculating the sum of A + B vectors, how will the answer change if you do it B + A
It will not! vector addition is commutative function
When calculating the subtraction of A - B vectors, how will the answer change if you do it B - A
Answer will have the same magnitude but be in the opposite direction
How is a scalar calculated from two vectors?
Dot product!
IAI IBI cos theta
How is a vector calculated from two vectors?
cross product
IAI IBI sin theta
Formula for gravitational force between two objects
Friction ______the movement of an object
opposes
which is always larger- the coefficient of kinetic friction or the coefficient of static friction?
coefficient of static friction
**objects “stick” until they start to move and then slide more easily
How do you find weight, given mass?
Fg (weight of an object)= m*g
When no net force is acting on an object
velocity:
acceleration:
no acceleration and constant velocity
Newton’s first law
a body in constant velocity will stay that way unless acted on by an outside force
aka law of inertia
Newton’s second law
an object will accelerate when a nonzero force acts on it
F=ma
Newton’s third law
For every action, there is an equal and opposite reaction
FAB=-FAB
What is the only force acting in both free fall and projectile motion
gravity
At what initial angle is the maximum horizontal displacement in a projectile possible?
At a 45 degree angle, this is when both sine and cosine are maximized
for an elevator to accelerate upward the tension on the elevator cable must be ______ than the weight of the elevator
greater
what are the SI units for power
Watts or kg * m^2/s^2
At what point after jumping horizontally out of a window is the angle between firefighters’ acceleration and velocity vectors greatest?
The instant the firefighter jumps
If a block is at rest on an inclined plane, what is the static force equal to? What is the equation for this?
The parallel component of gravity:
mg*sin(theta)
N are the SI base unit for force. True or false?
False, Newtons are the derived unit, but kg*m/s^2 is SI
In an electrochemical cell, electrons always flow from the _____ to the _______
anode to the cathode
Which halide makes a better leaving group: Fluoride or bromide?
Bromide-since it is larger
Which carbons do SN2 reactions normally occur on?
The least substituted
Attached to the least number of carbons
What is the general order of priority in naming of functional groups?
-Double-bonded Os and an O then N
-double O and H (aldehyde)
-Double O
-Alcohol
-Amine
Lewis bases are electron pair _____
donors
Lewis acids are electron pair______
acceptors
Both Arrhenius and Bronsted-lowry acids act as
H+ donors
How is a coordinate covalent bond formed?
By overlapping electron orbitals of an electron-rich atom and an electron-dificient atom
How many elements are attached to the central one in an octahedral?
6
Dipole-dipole interactions occur between
the partial charges of two permanent dipoles
Rank the strengths of noncovalent intteractions:
dipole-induced dipole
dipole-dipole (c=o)
ion-dipole
dipole-dipole (H with N,O,F)
dipole-induced dipole
dipole-dipole (c=o)
dipole-dipole (H with N,O,F)
ion-dipole
What is an Imine group?
C=N
What is decarboxylation?
The removal of a carboxyl group from a compound; carboxyl group is converted into CO2
What is lactonization
the condensation rxn between an alcohol and carboxylic acid that forms a cycic ester
Does stereochemistry change in hydrolysis products?
No
What is the best way to separate a racemic mixture?
add a resolving agent to change their physical properties by creating diastereomers
What are the differences between E/Z isomers
how do you calculate the median when even number of data points?
Take the two middle numbers and average
mode
the number that occurs the most often
When is mean not a good indicator of central tendency
when there are a good number of outliers
What does negative skew look like? Mean compared to the median and mode
tail to the left! Mean lower than median
mean«median«mode
mean is most effected by skew!
What does positive skew look like? Mean compared to median and mode
tail to the right! mean higher than median
mean»median»mode
SI units for kinetic energy
Name and units
Joule (kg*m^2)/s^2
kinetic energy equation
k=1/2mv^2
gravitational potential energy formula
U=mgh
Total mechanical energy equals
gravitational potential energy+kinetic energy
What are three nonconservative forces in physics
friction
air resistance
viscous drag
work is defined as
the process by which energy is transferred from one system to another
Given force, displacement, and angle between the force and displacement vector, how do you find work?
W= Fdcos theta
cos theta because work is SCALAR, so dot product!
if V is constant while P changes what work is done? What is this process called?
W=0
isovolumetric process
if P is constant while V changes what work is done? What is this process called?
W=P*change is V
isobaric process
Power and work relationship
P=W/t
Joules are the units for which two things
Work and Energy
How do you calculate the efficiency of a pulley system? (formula)
Efficiency=Win/Wout=(load)(load distance)/(effort)(effort distance)
As confidence level increases, a confidence interval
becomes wider
In uniform circular motion is there work? Why?
No work is done; the displacement vector and force vector are always perpendicular
If two people of varying masses (50kg and 80kg) jump from the same height onto a trampoline, who will bounce back higher?
they should both have the same height
ppm=
(mass of solute/mass of soln)*10^6
grams/grams *10^6= ppm
Common-ion effect
if two dissolved compounds have an ion in commmon, the equilibrium will shift towards the left (undissolved state)
solubility will decrease
Same ion= bad solubility
How to find Ksp
Ksp=[X]^b[Y]^c of ONLY PRODUCTS
the equilibrium position of solubility
What are the 5 levels of hybridization? Name the one in each category with 0 lone pairs
sp, linear
sp^2, trigonal planar
sp^3, tetrahedral
dsp^3, trogonal bipyramidal
d^2sp^3, octahedral
equilibrium of a reaction occurs when…
When the forward and reverse reactions occur at the same rate, not when they are at the same concentration
Towards which direction would SO4^2- and Na+ flow in a galvanic cell?
SO4^2- towards the anode and Na+ towards the cathode
In a galvanic cell delta G is____ and E cell is____
negative, positive
In an electrolytoc cell delta G is_____ and Ecell is_____
positive, negatove
Ecell definition
the voltage difference between the anode and cathode
A state function is independent of what
the path taken (process by which the state is achieved)
the state function is an intrinsic property
Combustion reaction general setup
some fuel (ch4) + o2-> CO2+H2O
In a single strand of nucleic acid, nucleotides are linked by what types of bonds?
phosphodiester bonds
The equation for change in length of a solid related to changes in temperature?
Change in length (Delta L)= aLdeltaT (alot!!)
a=coefficient of linear expansion
zeroth law of thermodynamics
no heat flows between objects in thermal equilibrium. If two systems are in thermal equilibrium, and one of those systems is in thermal equilibrium with a third system, then all 3 are in thermal equilibrium with each other
isolated vs closed system
Isolated; neither energy or matter is transferrd
closed: energy is transferred but matter is not
the internal energy of a system (Delta Q) equals
(first law of thermodynamics)
Q-W
work transferred into a system-work done by a system
second law of thermodynamics
objects in thermal contact with one another will attempt to reach thermal equilibrium by the one with a higher temp transferring heat to the one with a lower temp
How many Joules equal one Calorie (big C)? What does Calories measure, and how many little c calories is that equal to?
4184 J
One Calorie is amount of heat needed to raise 1 kg of water 1-degree celsius. Equal to 1000 nutritional calories (little c)
conduction
transfer of heat by one molecule colliding with another
convection
transfer of heat by the physical motion of a fluid (liquid or gas) over a material
Radiation
transfer of energy by electromagnetic waves
Specific heat of water
1 cal/g*K or 4.186 J/g *celsius
specific heat (q) equals
MCAT!
mcdelta T
c=specific heat of that substance
What happens to the internal temp of a substance going through a phase change when heat is added or removed from the system?
It does not change
equation for heat gained or lost by a material going through a phase change
mL
mass heat of transformation
either heat of fusion (solid<->liquid)
heat of vaporization (liquid<->gas)
Immiscible
two layers that do not mix
Extraction process
Dissolved substance in a solvent into a new solvent
2.Add in a new solvent that is immiscible (not mixable with original solvent) and shake
3.The dissolved substance will separate into either the aqueous phase (more polar) and the organic phase (less polar)
**(LIKE DISSOLVES LIKE—-If it is polar it will dissolve in polar (this only applied to polarity not acid/base)
4.Use a separatory funnel which will separate solvents based on density (denser first)
- Evaporate solvent using a rotary evaporator which will separate final desired substance
When would you use gravity filtration instead of vacuum filtration?
Gravity(aka simple): product of interest is the filtrate (the liquid)
Vacuum: product of interest is the solid
Does an acid dissolve better in aqueous acid or base? Does something more polar dissolve better in a polar or non-polar solvent?
The acid dissolves better in base
Polar dissolves better in polar
The acid/base and polarity dissolving properties are opposite
When to use vacuum distillation
Distill a liquid with a boiling point over 150 Celsius
Key concept of all types of chromatography
The more similar a compound is to its surroundings the more slowly it will move
Thin layer and paper chromatography: What characteristics of stationary phase? which molecules moves most slow?
The stationary phase is polar (silica gel for TLC and cellulose for paper)
More polar molecules will move more slow
Watts=
Joule/second
Adiabatic system definition and what the first law of thermodynamics reduces to
adiabatic= no heat exchange
Delta U=-W
Two substances have the same freezing and boiling points, but solid sample of substance A boils before substance B why could this be?
Substance B has a higher specific heat heat of vaporization, or heat of fusion
If a solvent system is 85:15 ethanol: methylene chloride where will the most polar substance be relative to the solvent front
closest to the solvent front because this is a reverse-phrase chromatography where the solvent system is polar
Brine is essentially
Salt water
What is the density of water in g/cm^3 and kg/m^3?
1 g/cm^3
1000 kg/m^3
Atomic weight vs atomic mass
Which is the one reported on the periodic table?
atomic mass: protons+neutrons
atomic weight: a weighted average of natural occurring isotopes
atomic weight is reported on the periodic table
As electrons go from a lower energy level to a higher energy level what happens?
They get AHED
Absorb light
Higher potential
Excited
Distant
Rutherfords view
atom has a dense positive nucleus that made up small amount of volume
Bohr model
a dense positive nucleus surrounded by electrons revolving around it at distinct intervals
What was Planck the first to describe?
Quantum levels of electrons
Heisenberg’s uncertainty principle
Impossible to perfectly determine both the accuracy and momentum of an electron
Pauli exclusion principle
no two electrons can possess the same set of four quantum numbers
Aufbau principle
Electrons fill from lower to higher energy and will fill completely before moving to the next subshell
Hund’s rule
Orbitals are all filled with 1/2 before completing the full orbital
What two elements and their groups don’t follow Hund’s rule? Why?
Copper and Chromium
It is more stable to complete or half-complete the d-orbitals then have a complete s -orbital of the one before
Which materials are paramagnetic and what does this cause
Paramagnetic materials are ones without paired electrons
Causes PARallel spin and attraction
Which materials are diamagnetic and what does this cause?
Diamagnetic materials are ones with only paired electrons
Causes magnetic repulsion
Valence electrons
electrons in the outermost shell
Pressure formula with force and area
F (normal vector)/A
Absolute pressure definition and formula
total pressure exerted on an object submerged in fluid
P=Po(pressure at the surface)+pgz (Density*gravity *depth)
what would happen on the liquid surface if adhesive and cohesive forces are equal
no meniscus would form
Which way is buoyant force directed?
always upward
The equation for buoyant force
Cohesion vs adhesion
cohesion= attractive force liquid molecules feel towards other molecules of the same liquid
adhesion=attractive force a liquid molecule feels toward molecules of a different substance
when would a backwards (convex) meniscus form?
When liquid cohesive forces are greater than adhesive forces
Specific gravity formula
Dynamic pressure definition and formula
pressure assoc. with flow
1/2densityspeed^2
**kinda like kinetic energy!
What is a pitot tube used to measure?
Measure static pressure during flow to calculate speed
Laminar flow
flow in which there are no eddies and in which streamlines are roughly parallel to each other
Turbulance
presence of backflow or current eddies
Continuity equation and what does it describe
Bernoulli’s equation
What would happen to flow rate in the following scenarios:
increased radius
increasing viscosity
increased length of the tube
increased pressure gradient
increased radius = increased flow rate
increased pressure gradient=increased flow rate
increasing viscosity=decreased flow rate
increased length of the tube=decreased flow rate
Think of traffic!!
What equation should be used for isolated segments of human circulation?
Pousille’s law
During exhalation how does the total resistance of the encountered airways change as air leaves the alveoli to escape the nose and mouth?
Total resistance increases even though diameter increases, because there are fewer airways in parallel with each other
Objects at the same depth must have the same
gauge pressure
How do you find tension on a chain of an anchor in the water given Force of gravity?
T=Fg-Fbuoy
Fbuoy= fluid density* fluid volume* gravity
two balls held beneath the surface with the same buoyant force but different masses will accelerate to the surface in which order?
one with smaller mass will accelerate and reach surface fastest
in connected horizontal pipes of different cross-sectional areas, which will have the lowest water level?
The one with the least cross-sectional area
According to Bernoulli’s equation, at the same heights, how are speed and pressure related
speed and pressure inversely related
When electrons are removed from a an element to form a cation, where are they take from first?
The highest n value
so ZN 2+
is [Ar] 4s^0 3d^10
not
[Ar]4s^2 3d ^8
What is the maximum number of electrons allowed in a single atomic energy level in terms of the principle quantum number n?
2n^2
What happens when an electron falls from n=4 to its ground state, n=1?
A photon is emitted
SI unit for charge and the fundamental unit of charge
Columb and the unit is
e=1.60*10^-19 C
Compare and contrast conductors and insulators
insulator: -doesn’t distribute charge equally over surface, does not easily transfer charge
Conductor: Distributes charge equally over its surface, and transfer charges
What are the two general types of conducting solutions?
-Ionic
-electrolyte
Coulomb’s law formula
Fe=kq1q2/r^2
Field vectors point ______ positive charges and _______ negative charges
Field vectors point away from positive charges and toward negative charges
What are two formulas that can be used to determine electric field magnitude?
E= Fe/q=kQ/r^2
E=electric field mag
Fe= electrostatic force
q=test charge
k=electrostatic constant
Q=source charge magnitude
r=radius between two charges
Formula for electric potential energy
U=kQq/r
Units for electrical potential
Volts, 1 J/C
Formula for electric potential
V=kQ/r
difference between electric potential and electric potential energy
electric potential: ratio of the magnitude of a charges electric potential energy to the magnitude of the charge itself
electric potential energy: a form of potential energy that is dependent on relative position of one charged compared to another charge or group of charges
Voltage equals
Va-Vb=Wab/q
work needed to move a test charge q through an electric field from point a to point b.
Or the difference in volts between these two points(Va-Vb
Which direction do positive charges spontaneously move
In the direction that decreases electric potential (negative voltage)
Which direction do negative charges spontaneously move related to electric potential
In the direction that increases electric potential (positive voltage)
equipotent line
a line on which the potential energy at energy point in the same
Given what two things could help you find dipole moment? Dipole moment formula
p=qd
p=dipole moment (SI Cm)
q=charge
d=distance
What is the behavior of an electric dipole when exposed to an external electric field
A dipole will rotate within an external electric field such that its dipole moment aligns with the field
The formula for magnitude of a magnetic field
B= mag. of magnetic field
Mo=permeability of free space
I=current
r=distance from wire
Charge moving in these two directions will experience no force from the magnetic field
parallel, anti-parallel
For a straight wire, what is the magnitude of the force created by an external magnetic field
FB=ILBsin theta
I=current
L=length of wire
B= magnitude of magnetic field
In reference to an electric field’s vector, which direction will an electron feel a force
opposite direction of the electric field vector,
if positive it would have been same direction as electric field vector
because it points in the same direction as the positive test charge
Define current
The flow of POSITIVE charge
Conductivity is reciprocal of
voltage, units is seimens
How does metallic conductivity work?
Equal distribution of free electrons across all neutral atoms in a atomic mass
Current formula, and SI
I=Q/delta time
I=current
Q=amount of charge passing through a conductor
Unit: Ampere (1A=C/s)
Kirchhoff’s Junction Rule
Iin=Iout
sum of currents entering a junction=sum of currents leaving that junction
Kirchhoff’s Loop Rule
In a closed-circuit loop, the sum of voltage sources will always be equal to the sum of voltage drops
True or false: In a circuit, the number of electrons entering a point and leaving a point are the same
True; Kirchhoff’s junction rule
Resistance
Opposition to the movement and flow of charge
What can lightbulbs and other appliances be categorized as in a circuit?
Resistors
Units for resistivity
meters*ohms
If a resistor doubles in length it______ resistance
it doubles resistance
As you increase the cross-sectional area of a resistor what happens to the resistance
decreases, because you are increasing the number of conduction pathways through the reistor
Voltage drop (V)=
I*R
I= current
R= Magnitude of the resistance measured in ohms
Power of a resistor can be calculated which 3 ways?
1) IV
2)I^2R
3) V^2/R
In series, the total voltage drop will be equal to
the sum of the voltage drops at each resistor
How does adding/removing a resistor affect total resistance in a series?
adding=increases
removing=decreases
How does adding/removing a resistor affect total resistance in parallel?
adding=decreases
removing=increases
What 4 factors impact the resistance of a resistor
resistivity, cross-sectional area, length, temperature
The capacitance of parallel plates formula
C=eo (A/d)
eo=8.85*10^-12 F/m and is the permittivity of free space
A= area of overlap of the two plates
d=separation of the two plates
The uniform electric field between two plates can be calculated as
E=V/d
Potential energy stored in a capacitator
U=1/2CV^2
Dielectrics between the plates of a capacitator in circuit will cause
increased capacitance by a factor of k (dielectric constant) and increased charge on the capacitors
Formula for calculating capacitance with a dielectric
C=Akeo/d
Capacitors are CAKED with charge
Dielectrics between the plates of a capacitator in the circuit will cause
increased capacitance by a factor of k (dielectric constant) and increased charge on the capacitors
When capacitors are connected in series total capacitance_____
When capacitors are connected in parallel total capacitance_____
When capacitors are connected in series total capacitance decreases
When capacitors are connected in parallel total capacitance increases
Ammeters measure ______ and placed in _____to measure point of interest
Ammeters measure current and placed in series to measure point of interest
voltmeters measure ______ and placed in _____with circuit element of interest
measure potential difference (voltage)and placed in parallel to measure point of interest
Divalent cation
cation with a valence of 2+
What periodic category is most likely to form a complex ion with H2O
Transition metals
Periodic table:
groups/familys are _______
periods are _______
groups=column
period=row
Effective nuclear charge
the strength on which protons can pull on electrons
sodium-potassium pump direction/quantities
Moves three sodium ions out of the cell for every two potassium ions it lets into the cell
what will distill first during fractional distillation: hexanoic acid or ethyl hexanoate?
ethyl hexanoate bc it has weaker intermolecular forces and a lower boiling point
Are atomic mass units equal to grams?
No, amus are defined as 1/12 the mass contained ina carbon-12 atom (~1g)
6.02*10^23 amu=1 mole of amu=1.00g
Superheating
The liquid is heated past its boiling point but does not boil
What do boiling chips in simple distillation help with?
Providing sites for bubble formation, overcoming the surface tension so the liquid boils evenly
Butanone structure
-one ending is just a double bonded O- think acetone structure too!
Ester structure
What are the outcomes of boh the Strecker synthesis and gabriel synthesis?
The result is a mixture of L- and D- forms of amino acids
What does a Fischer esterification use as reactants?
A carboxylic acid and alcohol
What 3 things does boiling point depend on?
intermolecular forces, molecular weight, and branching
If something has low electronegativity than it has high_______
electropositivity
Zeff definition
the electrostatic attraction between the valance shell electrons and the nucleus is known as the effective nuclear charge
Ionization energy definition
The energy required to remove an electron from a gaseous species
First ionization energy will always be______ than the second ionization energy
smaller
Electron affinity
the energy released by a gaseous species when it gains an electron
Electronegativity definition
The attractive force that an atom will exert on an electron in a chemical bond
Acetone structure
In the doppler effect equation, when do you use the top sign (+) and when do you use the bottom (-)?
The top is for toward: if you are moving toward the sound
The bottom is away
Which is the major product (this is NP-HPLC)?
The largest hump, the area under the curve is proportional to the quantity of material collected
In a chair structure wedges are ____ and dashes are ______
Wedges: up
Dashes: down
This is what type of interaction?
dipole-induced dipole; the H3 has no strong dipole moment,
Given g/L and % solute in it, how do you find mol/L of solute?
g/L *(%-> decimal ie 3.5%-> 0.035 g)= g of solute
g solute/ molar mass solute= mols
mols/ 1L (1 L is given since already now % in quantity!!)
What is beta decay?
In beta decay neutron becomes a proton and an electron is emitted
mass stays same
element changes 1 up
and electron is emitted
How do you find the magnitude of force experienced by the foot due to the ground when turning?
Need Fnormal (mg) and Fturn (mturning acceleration)
right triangle!!!
Fcombined= [(Fnormal)^2 + (Fturning)^2]^1/2
What is an oxidoreductase?
transfer electrons from one molecule to another (normally will see addition/subtraction of Os or Hs)
What are the 2 important spectroscopy peaks and where are they located?
The angle of incidence will always equal what?
the angle of reflection
What would be the equilibrium constant of the dissociation reaction given Ka?
1/Ka
this is dissociation so opposite
if asked of forward reaction, would have just been Ka
How will the number of electrons in an atom change after Beta decay?
Stays the same!! Even though an electron is emitted, it is a Nucleus created electron (from a neutron-> proton+ electron
so the number of total electrons stays the same
What is the graph relationship between Log(Pw) and 1/T?
y=mx+b
Back to basics!!!
A concave mirror creates a _____ image of an object positioned outside the mirror’s focal length
real
A laser with ______wavelength refracts less light when passing from air into glass, and therefore the angle of refraction is _______from normal
longer wavelength; further from normal.
This involves snell’s law:
n1sin (theta)1=n2sin(theta)2
Which direction is the force acting on a moving charge inside a magnetic field?
Lonentz force is perpendicular to magnetic force and velocity of the charge
What formula can be used to find sound decibels?
dB are logarithmic!
dB=1olog10 (I1/I2)
How will the work done by the Lorentz force on an electron traveling through the magnetic field of an MRI scanner change if the magnetic field strength is increased?
The work will not change, because it is always 0
cos(90)=0!! Therefore work done perpendicular has no effect
When does pH = pKa? also describe this location on a titration curve
when [B]=[A]
this occurs at the midle of the plateau
How are volumetric flow rate and poiseuille’s law related?
Gibbs free energy of a reduction-oxidation reaction formula
What is the formula for osmotic pressure?
On an H NMR spectra, adding an electronegative group nearby to protons of interest will _______them, and cause a _______shift on the NMR spectra
On an H NMR spectra, adding an electronegative group nearby to protons of interest will deshield them, and cause a downward shift on the NMR spectra
What is the equation for the doppler effect?
ADP vs AMP vs ATP structure
What are the units for lens strength?
Diopter, and measured in m-1
Define a salt bridge
form from ion-ion interactions between two oppositely charged side chains in a protein
In what scenarios do london dispersion forces tend to be the strongest
in larger molecules with larger more pronounced electron clouds
What happens in electron capture
an electron is captured, and the atomic number decreases by 1 (similar to positron emission)
Which generally have higher second ionization energies? metals or non-metals
metals; however, lower for group 2 then group 1 because you would be taking a core electron
Where is the transition state of the 1st step in this reaction
where the ++ is
How do you determine activation energy in a multi-step reaction
the one with the highest energy transition state is the Ea
Which of these 4 substances will elute first in gas-liquid chromatograph
the 2-methyl butene, bc nonpolar, lower boiling point
What amino acids would likely bond to ADP?
Arginine, histidine, and lysine, because of their interactions with the negatively charged oxygens on ADP
What does Henry’s law of solubility show about relationship between gas solubility and volume?
law of mass action
the rate of each rxn is proportional to the concentrations of each component raised to the power of the reaction order
If delta H is negative, what would you expect a temperature vs time graph to look like?
Hess’ Law
As order (organization) increases…
entropy decreases
increase in oxidation state is
oxidized,
decreased=reduced
Ways to remember gas laws
CTGPBV
C= T and V
G= T and P
B= P and V
Can these guys possibly be victorious?
Not Always victorious
Avagadros: n and V
Describe the shifts in the bicarbonate buffer system according to hyper and hypo ventilation
An uncatalyzed rxn has a higher Ea and therefore what effect on the rate constant?
smaller rate constant
London Dispersion forces are greater in smaller or bigger molecules
bigger! More inducible
What are the stability trends as more alkyl groups are added to a carbanion and a carbocation?
What is a graph look like of applied force vs friction (kinetic and static)
Boiling point is a measure of what
Intermolecular forces NOT intra
heat of combustion would better measure thermodynamic stability of a molecule
Answer is C.
monosodium is the weak acid and disodium is the weak base. To make more acidic,
What is acetylation
addition of an acetyl group at the shown carbon squiggle
Porphyric
What does not change as a wave moves through a medium?
Frequency; Frequency is an inherent, defining property of a wave; a 50 Hz wave is a 50 Hz wave, but it can be a variety of wavelengths depending on the medium it moves through, and as a result, the speed at which it is moving.
What are two ways to solve this problem?
- Pressure= densitygravityheight
- Dimensional analysis: just multiply the density by gravity and you would have the right units cancel out
How is an amino acid formed in a strecker reaction?
Aldehyde + ammonia
Describe the reaction of oxygen with tosylate or mesylate that makes it a better leaving group
fatty acyl group
a carbonyl and hydrocarbon chain
How are eclipsed conformations shown on an energy plot
Bulbs connected in series will have _____ current, and ______ power/voltage
equal current, but decreasing power/voltage
How to find kinetic energy of a gas molecule given Boltzman’s equation
Aldol addition vs aldol condensation
aldol addition: first part of an aldol condensation, rxn between ketones and/or aldehyde
aldol condensation: aldol addition followed by dehydration
The product of strecker synthesis is
racemic (D,L)
Thermodynamic vs kinetic products
Kinetic: formed on least substituted, bulky base (LDA), low temps, faster
thermo: formed on most substituted, small base (NaH), high temps, slower
what can x be used to calculate in motion/kinetic physics problems?
It can be used to find either vertical or horizontal displacement!!
How would you calculate the overall efficiency of each step in a kinetic chain?
multiply all the efficiencies by each other
In total internal reflection what is true about the incident angles
it is greater than the critical angle
Given ksp, how can you find molar solubility?
Structure of a sulfonyl functional group
Structure of a nitro functional group
Nearsighted vision aka _______, and where images form where in relationship to the lens?
myopia; in front!!
Lens strength formula
How can you tell whether something is a conjugate acid or base?
If the initial molecule has one less H, than the substance is the conjugate base. One additional= conjugate acid
An acid differs from its conjugate base only by the presence of an additional H+. A base differs from its conjugate acid only in the lack of a single H+
O and H did not change oxidation numbers, so they could not have been oxidized or reduced
When determining a balanced equation, what are the TWO things you have to look at?
- The elements balance out
- AND the charge balances out!!! (I’ve messed this up a few times)
Bond enthalpy= bond dissociation energy
so bonds formed have negative bond enthalpy
What are 3 characteristics of an ideal fluid?
Energy carried by a mechanical wave is dependent only on
amplitude!!! Independent of wavelength and frequency
What are two main distinctions in resistors in parallel vs series?
Parallel: All have same current (conservation of charge)
Series: All have same voltage, but different currents
Decomposition reaction
the break down of a single compound to 2 or more new compounds
Decomposition reaction
the break down of a single compound to 2 or more new compounds
How to calculate Zeff
Zeff=protons-core electrons
if greater, than greater Zeff
In the formula for osmotic pressure, what does i symbolize?
the number of species an ion will formed when dissolved
Combustion reaction
How does intensity of sound vary as it moves further from a stationary source
I=P/A
A= 4pir^2
For a salt bridge, anions migrate toward the _______ and cations migrate towards ________
For a salt bridge, anions migrate toward the anion and cations migrate towards cathode
How do you calculate lens strength?
S=1/f=1/o+1/i
Given Kb and equilibrium concentration of reactant how do you find equilibrium concentration of product?
kb= prod/reactants
imine vs amine
Describe the differences between ordered random and ping-pong substrate binding
What is the relationship between equatorial/axial and dash/wedge
They vary! One is not set
What are the additional rules of unsaturation (in addition to CnH2n+2 rule
Really simplified, degrees =complete expected saturated H-(actual H/2)
How does a Fischer esterification work?
combine carboxylic acid, alcohol, acid, and heat in a condensation reaction
Stereochemistry at the star?
Down (in equatorial or axial!) Is dashed
Stereochemistry of the star?
What is required of a carboxylic acid in order to undergo decarboxylation?
A Beta-Carbonyl!!
What does a grignard reagant do?
Convert ketones or aldehydes to alcohols. Grignard reagents are organomagnesium-halide (R-Mg(halide))
What are the expected products of an aldol reaction vs an aldol condensation?
Adding 1 and 2 equivalents of base (OH-) to aldehydes and ketones produces (name and describe 4 different products)
What does a retro-aldol rxn do?
Tautomerization of an imine forms a
enamine
smaller or larger molecules will migrate further across the gel in gel electrophoresis
smaller/more compact
If when all samples are denatured during gel electrophoresis and they travel the same distance this indicates they
have the same number of nucleotides. In picture, all samples have the same number of nucleotides, but the HP mutant is more compact
In a doppler ultrasound what is held constant?
Vo, since the person isn’t moving
What factors impact resistance?
type of material, temperature (higher/greater), length (longer/greater), area (wider/smaller)
Longer wavelengths refract_____light and have a _______ index of refraction
less, and have a smaller index of refraction
electrons do not equal heat
What are the directions of electric field, magnetic field, and lorentz force?
They are all perpendicular to each other (right hand rule)
Oxidized molecules change to a _____oxidation state
reduced molecules change to a _______oxidation state
higher oxidation state (oxidized =^oxidation state)
how to find standard reduction potential
1) flip signs to be correct for equation
2) add these values
Erxn=Ered+Eox
Adding an ____ to a solution that produces an aqueous base will shift equilbrium forward; vice versa is true for aqueous acid
acid
Key LeChatlier Shifts
How to classify L or D on sugars
chiral carbon furthest from the anomeric carbon-> if R than D if L than S
How are ketals and acetals formed?
acid-catalyzed nucleophilic addition of two alcohols to a ketone or aldehyde
How is wax formed?
Explain examples of when a retro-aldol reaction would create 2 ketones, an aldehyde and a ketone, or two aldehydes
addition of a primary amine to a ketone or aldehyde produces an
imine
addition of a secondary amine to a ketone or aldehyde produces an
enamine
What is the molecular geometry of XeO3?
What are the conversion factors between pressures?
In a coordinate covalent system what acts as lewis bases and lewis acids?
the center is a lewis acid! counterintuitive since normally metals, so be careful!!
What are the products of triglyceride saponification?
How does cholesterol structure differ from structures of phospholipids, triglycerides, and fatty acids?
What is the structure of flavin?
Common structures to be familiar with
The original band should ALSO decrease over time
Formate vs carbonate vs bicarbonate vs acetate
Formate: H!- HCO2
Carbonate: CO3
Bicarbonate: HCO3- (think bicarbonate buffer system)
Acetate: CH3CO2
