Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MCAT > CHEMISTRY/ORGANIC CHEMISTRY FINAL REVIEW > Flashcards

CHEMISTRY/ORGANIC CHEMISTRY FINAL REVIEW Flashcards

You may prefer our related Brainscape-certified flashcards:
MCAT flashcards
1
Q

Atomic number

A

Z - number of protons found in an atom of that element

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mass number

A

A - sum of the protons and neutrons in the atom’s nucleus

-varies in isotopes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Planck relation

A

E = hf

Energy is related to frequency times Planck’s constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Principal quantum number, maximum number of electrons per number

A

n - indicates the electron’s shell

Maximum number of electrons within a shell = 2n^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Azimuthal quantum number, range of possible values

A

l - shape and number of subshells

range of possible values: 0 to n-1

  • only one subshell in first principal energy level (0)
  • two in second principal energy level
  • three in third principal quantum level

indicated as a letter (s,p,d,f)

Maximum number of electrons within a subshell = 4l + 2 (s2,p6,d10,f14)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Magnetic quantum number, range of possible values

A

ml - specifies the electrons orbital

range of possible values: -l to l

orbitals in s are spheral, p are dumbbell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Spin quantum number

A

ms - designated +½ or -½

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Electron configuration determination and description

A

2p4 indicates that there are four electrons in the second (p) subshell of the second principal energy level

Read the periodic table to determine electron configuration

-lowest s is 1s, lowest p is 2p, lowest d is 3d, lowest f is 4f

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Hund’s rule and implications, special elements

A

finding a seat on a crowded bus, electrons find their own orbital

half-filled and fully filled orbitals have more stability

chromium and copper groups are therefore exceptions to electron configuration, moving an electron from s to d

chromium = 4s13d5

copper = 4s13d10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

paramagnetic vs diamagnetic

A

paramagnetic materials have unpaired electrons and are weakly attracted to the magnetic field

diamagnetic materials have only paired electrons and will be slightly repelled to the magnetic field

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

A elements and B elements

A

A elements are representative elements and include groups 1A through 8A (everything but transition elements and bottom of periodic table)

B elements are nonrepresentative elements and include the transition elements and lanthanide and actinide series

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Effective nuclear charge trend and equation

A

indicates the electrostatic attraction between the valence shell electrons and the nucleus

increases from right to left, as one moves down a group principal quantum number increases and Zeff is more or less constant

Zeff = Z(atomic number) - S(non-valence electrons)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Atomic and ionic radii definition and trend

A

atomic radius decreases from left to right and from bottom to top

ionic radii of metals near the metalloid line is dramatically smaller than that of other metals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Ionization energy definition and trend

A

energy required to remove an electron from a gaseous species

-removing an electron is an endothermic process

increases from left to right and from bottom to top

groups 1 and 2 are called active metals for their low ionization energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Electron affinity definition and trend

A

the energy dissipated by a gaseous species when it gains an electron, opposite of ionization energy

increases from left to right and from bottom to top

noble gases have extremely small electron affinities however

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Electronegativity definition and trend

A

the attractive force generated in a chemical bond

increases from left to right and from bottom to top

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Alkali metals

A

largest atomic radii, react readily with nonmetals to lose an electron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Alkaline earth metals

A

two electrons in valence shell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Chalcogens

A

Oxygen group not as reactive as halogens but crucial in biology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Halogens

A

desperate to complete their octets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Noble gases

A

inert

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Transition metals

A

low electron affinities, ionization energies, and electronegativities have different possible oxidation states

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Exceptions to the octet rule and examples

A

Incomplete octet hydrogen, helium, and lithium (2), beryllium (4), boron (6)

Expanded octet

-Any element in period 3 and greater can hold more than 8 electrons, including phosphorus (10), sulfur (12), chlorine (14), and others

Odd numbers of electrons Ex: NO has eleven valence electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Coordinate covalent bond

A

If both of the shared electrons are contributed by only one of the two atoms, that is a coordinate covalent bond

once it is formed it is indistinguishable from any other covalent bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Ionic bonds in solid state

A

In solid state, the ionic constituents of the compound form a crystalline lattice of repeating positive and negative ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Formal charge calculation

A

Valence shell - dots - dashes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Lewis structures steps

A

Draw out backbone with the least electronegative atom in the center

Count all the valence electrons

Complete the octets of all atoms bonded to the central atom, using the remaining valence electrons left to be assigned

Place any extra electrons on the central atom

VSEPR Theory Arrange the electron pairs around the central atom so that they are as far apart as possible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Electronic geometry

A

Spatial arrangement of all pairs of electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Molecular geometry

A

spatial arrangement of only the bonding pairs of electrons

determined by coordinate number -number of atoms that surround and are bonded to a central atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Hydrogen bonds

A

Even hydrogen bonds have only about 10 percent the strength of a covalent bond

Nitrogen, Oxygen, or fluorine bonded to hydrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Moles calculation

A

Moles = mass of sample/ molar mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Gram equivalent weight

A

the amount of a compound, measured in grams, that produces one equivalent of the particle of interest

Gram equivalent weight = molar mass/n where n is the number of particles of interest produced or consumed

Ex: gram equivalent weight of H2Co3 is half of its molar mass with interest towards h+ ions

Useful for acid-base chemistry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Normality

A

equivalents/L (where molarity is moles per liter)

most commonly used for hydrogen ions concentration

Ex: A 1N solution of acid would be like HCL, and 2N would be like H2So4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Molarity

A

Normality/n or moles per liter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Empirical formula

A

gives the simplest whole-number ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Combustion reaction

A

involves a fuel (usually hydrocarbon) and a oxidant (normally oxygen), forming carbon dioxide and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Neutralization reactions

A

a specific type of double-displacement reaction: acid + base = water + salt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Cations and Ions naming (metals, less charge, more charge, monatomic, less oxygen, more oxygen)

A

For metals the charge is indicated by a Roman numeral in parentheses

  • ous: less charge, -ic: greater charge
  • ide: monatomic anions

Hypo- indicates less oxygen, per- indicates more oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Formula and Charge:

Acetate, Cyanide Permanagante, Chromate, Dichromate, Borate, Ammonium, Thiocyanate

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

When is a solute considered a strong electrolyte?

A

A solute is considered a strong electrolyte if it dissociates completely into its constituent ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Arrhenius equation takeaways

A

k = Ae^(-Ea/RT) k is the rate constant, A is the frequency factor, Ea is the activation energy of the reaction, R is the ideal gas constant, and T is the temperature in kelvins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Transition state energy

A

Transition state/activation complex has greater energy than both the reactants and the products and is denoted by the symbol ‡

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Homogenous catalysis

A

the catalyst is in the same phase as the reactants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

heterogeneous catalysis

A

the catalyst is in a distinct phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Determination of rate law

A

For the general reaction aA + bB -> cC + dD, rate = k[A]^x[B]^y The values of x and y are almost never the same as the stoichiometric coefficients, the orders of a reaction must be determined experimentally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Mixed-order/broken-order reactions

A

refer to either non-integer orders (fractions) or to reactions with varying rate orders

fractions are specifically described as broken-order

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

law of mass action (determining Keq from concentration)

A

For a generic reversible reaction aA + bB ⇔ cC + dD, if the system is at equilibrium constant temperature

Keq = [C]^c[D]^d / [A]^a[B]^b

products over reactants

Keq = (x)^2/1-x

  • if x amount of A has reacted and x amount of B and C have been produced, and 1 is the starting concentration
  • can be rounded so the denominator is simply the starting concentration (in this case 1)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Types of systems and energy/matter exchange

A

Isolated System cannot exchange energy or matter with surroundings

Closed System can exchange energy but not matter with surroundings

Open System can exchange energy or matter with surrounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

First law of thermodynamics

A

Change in internal energy can only occur through heat or work

ΔU = Q - W

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Isothermal processes

A

Constant temperature, Internal energy is constant

ΔU = 0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Adiabatic processes

A

no heat exchanged between the system and environment

ΔU = - W

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Isobaric processes

A

constant pressure does not alter the first law, but appears as a flat line on a P-V graph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Isovolumetric (Isochoric) processes

A

constant volume

ΔU = Q

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

State functions

A

describe the system in an equilibrium state without respect to process

Pressure, density, temperature, volume, enthalpy, internal energy, Gibbs free energy, entropy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Standard conditions vs standard temperature and pressure

A

Standard conditions: 298K 1atm and 1 M concentrations

Standard temperature and pressure (STP): 273K and 1 atm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Phase diagrams- critical point

A

the temperature and pressure above which there is no distinction between the phases

-supercritical fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Enthalpy, Change in Enthalpy equation

A

equivalent to heat under constant pressure (an assumption the MCAT usually makes)

ΔHrxn = Hproducts - Hreactants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Equation for heat change, specific heat of water

A

q = mcΔT

specific heat of water = 1cal/g*K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

definition of heat capacity

A

the product mc, mass times specific heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Bomb calorimeter

A

constant-volume calorimetry
Because W = PΔV, no work is done in an isovolumetric process, and (ΔU = Q)

Also an adiabatic process, no heat is exchanged between the calorimeter and the rest of the universe, but it is exchanged between the steel decomposition vessel and the surrounding water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Equation for heat required for phase change

A

q=mL

m is mass and L is latent heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Entropy, second law of thermodynamics

A

time’s arrow, entropy always increases if not hindered from doing so

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Entropy equation (heat and temperature)

A

ΔS = Qrev/T

change in entropy = heat gained or lost in a reversible process/ Temperature in Kelvin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Gibbs free energy equation

A

ΔG = ΔH - TΔS get higher test scores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Free energy change equations with K

A

ΔGrxn = -RTlnK deriving the standard free energy change for a reaction

ΔGrxn = -RTlnQ/K deriving the free energy change for a reaction not at equilibrium K is equilibrium constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

atm to mmHG to torr to kPA

A

1 atm = 760mmHG = 760 torr = 100kPA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

when to use STP or standard state conditions

A

STP is generally used for gas law calculations; standard state conditions are used when measuring standard enthalpy, entropy, free energy changes, and electrochemical cell voltage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

ideal gas law

A

PV=nRT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

density equation, density gas equation

A

p (density) = mass/Volume = PM/RT

density = pressure*molar mass / R*Temperature

R = 0.0821 liter·atm/mol·K

R = 8.3145 J/mol·K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

constant relationships of gas exchange

A

PV/T is constant, PV is constant, V/T is constant, n/V is constant and equals k (moles/volume is constant)

-these can all be derived from the PV=nRT equation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Molar mass of gas calculation

A

M = (Density@STP) * 22.4L/mol

Molar Mass can be calculated as the product of the gases density at STP and the STP volume of one mole of gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Partial Pressures equations

A

Pt = Pa + Pb + Pc

Partial pressure of gas is related to its mole fraction

Partial pressure = moles of gas A / total moles of gas

The relationship between concentration and pressure is constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

Kinetic molecular theory assumptions

A

explains the behavior of gases

Assumptions

1 Particles have negligible volume

2 There is no intermolecular attractions or repulsions

3 Particles are in continuous, random motion, undergoing collisions with other particles and the container walls

4 Collisions between any two gas particles are elastic, with conservation of both momentum and kinetic energy

5 The average kinetic energy of gas particles is proportional to the absolute temperature of the gas, and is the same for all gases at a given temperature, irrespective of chemical identity or atomic mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

two Average molecular speed of gas equation

A

KE = 1/2mv^2 = 3/2kBT proportional to 3/2 the absolute temperature of the gas and Boltzmann constant

uRMS = sqr(3RT/M) M is molar mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Diffusion calculation from molar mass

A

Graham’s law: under isothermal and isobaric conditions, the rate at which two gases diffuse are inversely proportional to the square roots of their molar masses

r1/r2 = sqr(M2/M1) r is the diffusion rate, M is the molar mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Effusion calculation

A

the rates of effusion are proportional to the average speeds

77
Q

van der Waals equation of state purpose

A

corrects the ideal gas law of intermolecular attractions and molecular volume

78
Q

Solvation

A

Solvation is the electrostatic interaction between solute and solvent molecules.

This is also known as dissolution, and when water is the solvent it can be called hydration

Sparingly soluble salts dissolve minimally in the solvent

79
Q

how is H+ found in solution?

A

H+ is never found alone in solution, it is found bonded to an electron pair donor in a coordinate covalent bond

80
Q

7 General solubility rules

A

All salts containing Ammonium and alkali metal cations are water-soluble

All salts containing nitrate (NO3-) and acetate (CH3COO-) anions are water-soluble

Halides excluding fluorides are water-soluble, with the exception of those formed with Ag+, Pb2+, and Hg2+

All salts of the sulfate ion (SO4) are water soluble, with the exceptions of those formed with Ca, Sr, Ba, and Pb

All metal oxides are insoluble, with the exception of those formed with the alkali metals, ammonium, and CaO, SrO, and BaO

All hydroxides are insoluble, with the exception of those formed with the alkali metals, ammonium, and Ca2+, Sr2+, and Ba2+

All carbonates, phosphates, sulfides, and sulfites are insoluble, with the exception of those formed with the alkali metals and ammonium

WE WON’T BE EXPECTED TO MEMORIZE THESE RULES, BUT ALL GROUP 1 METALS SALTS AND ALL NITRATE SALTS ARE SOLUBLE

81
Q

Complex ion formation

A

Complexes are held together with coordinate covalent bonds

In some complexes, the central cation can be bonded to the same ligand in multiple places (chelation)

-generally requires large organic ligands that can double back to form a second (or even third) bond with the central cation

82
Q

Molality

A

Moles/kilogram

83
Q

Normality

A

reaction dependent, equal to the number of equivalents of interest per liter of solution

84
Q

Solubility product constants and ion product

A

Ksp = [A^n+]^m[B^m-]^n

-does not take into account solid compounds

ion product (IP)

  • analogous to the reaction quotient Q for other chemical reactions
  • same form as the equation for the solubility product constant but the values aren’t at equilibrium
85
Q

Common ion effect

A

reduction in molar solubility with the addition of common ions

86
Q

Colligative properties, name them

A

Properties dependent on concentration but not chemical identity

Vapor pressure, boiling point elevation and freezing point depression, osmotic pressure

87
Q

Vapor pressure equation

A

Mole fraction of solvents * Vapor pressure of solvent in pure state

88
Q

Boiling point elevation and freezing point depression equation

A

iKm

m is molality, moles/kg

value is negative for freezing point

89
Q

Osmotic pressure equation

A

iMRT

M is molarity, i = van’t Hoff factor

90
Q

Arrhenius acid/base

A

dissociate H+ in solution or dissociate OH- in solution c

ontain either H at the beginning of their formula or OH at the end

91
Q

Bronsted-Lowry acid/base

A

donates H+ or accepts H+ not limited to aqueous solutions conjugate base pairs

92
Q

Lewis acid/base

A

electron pair acceptor (acid) or electron pair donor (base)

same chemistry as coordinate covalent bond formation, complex ion formation, or nucleophile-electrophile interactions

(nucleophile is a base, electrophile is an acid)

93
Q

nomenclature anion to acid (with respect to oxygen)

A

if the anion ends in -ite (less oxygen), then the acid will end with -ous acid

If the anion ends in -ate (more oxygen), then the acid will end with -ic acid

94
Q

Water dissociation constant Kw

A

Kw = [H3O+][OH-] = 10^-14 @ 298K

95
Q

Estimating pH

A

if H+ is .001 or 10^-3 , pH = 3 -log(n*10^-m) = m-1.10-n or m-.n dissociation of strong acids and bases is said to go to completion

96
Q

Strong acids

A

HCl (Hydrochloric acid)

HBr (Hydrobromic acid

H2SO4 (Sulfuric acid)

HNO3 (Nitric acid)

HCLO4 (Perchloric Acid)

97
Q

Strong bases

A

NaOH (sodium hydroxide)

KOH (potassium hydroxide)

98
Q

Activity of Weak Acids and Bases (Ka and Kb)

A

Ka = [H3O][A-] / [HA]

Kb = [B+][OH-] / [BOH]

Ka and Kb are mostly used to determine the concentration of one of the species at equilibrium

99
Q

Salt formation, varying strengths acids + varying strengths bases

A

Strong acid + strong base: HCl + NaOH -> NaCl + H2O

Strong acid + weak base: HCl + NH3 -> NH4Cl

Weak acid + strong base: HCLO + NaOH -> NaClO + H2O

Weak acid + weak base: HCLO + NH3 -> NH4ClO

100
Q

Understanding titrations

A

At the equivalence point, the number of equivalents of acid and base are equal

NormalityA * VolumeA = NormalityB * VolumeB

Indicators are weak organic acids or bases that have different colors in their protonated and deprotonated states

Polyvalent acids and bases yield multiple equivalence points

-at each half-equivalence points, half of a given species has been protonated or deprotonated

101
Q

Bicarbonate buffer system

A

Co2 <=> H2CO3 ⇔ H+ + HCO3-

102
Q

Henderson Hasselbach equation

A

For a weak acid buffer solution

pH = pKa + log [A-]/[HA]

For a weak base buffer solution

pOH = pKb + log [B+]/[BOH]

remember concentration ratio as products over reactants

If the concentration of both the acid and conjugate base were double the buffering capacity would double, not the pH

103
Q

Assigning oxidation numbers

A

the oxidation number of a free element is zero

the oxidation number for a monatomic ion is equal to the charge of the ion

the sum of the oxidation numbers in a compound must add to that compounds charge

104
Q

Electrochemical cells, location of oxidation/reduction and pathway of electron

A

contained systems in which oxidation-reduction reactions occur

oxidation always occurs at the anode, and reduction occurs at the cathode

electron always travels from anode to cathode

105
Q

Galvanic cell, description, charge of anode and cathode, spontaneity etc

A

all the batteries you own

spontaneous, + emf, -ΔG

in a galvanic cell the anode is negative and the cathode is positive

has an aqueous electrolyte solution composed of cations and anions, the charge gradient is dissipated by the presence of a salt bridge, which contains ions that will not react with the electrodes or with the ions in solution

106
Q

Electrolytic cell, description, charge of anode and cathode, spontaneity etc

A

opposite of galvanic cells, except for An Ox Red Cat and anode-> cathode

driven by an external battery source, known as electrolysis

nonspontaneous, - emf, +ΔG

in an electrolytic cell the anode is positive and the cathode is negative

107
Q

Construction of cell diagram

A

shorthand notation representing the reactions in an electrochemical cell

Ex: Zn (s) | Zn2+ (1M) || Cu2+ (1M) | Cu (s)

  1. The reactants and products are always listed from left to right in anode | anode solution (concentration) || cathode solution (concentration) | cathode
  2. A single vertical line indicates a phase boundary whereas a double vertical line indicates the presence of a salt bridge or other barrier
108
Q

Faraday constant

A

10^5 C/mol e-

109
Q

Electrodeposition equation

A

mol M = It/nF

mol metal ion being deposited = current * time / 10^5 * number of electron equivalents for a specific metal ion

OR

mol e- = It/10^5

110
Q

Concentration cells

A

a type of galvanic cell, contains two half-cells connected by a conductive material allowing a spontaneous oxidation-reduction to proceed, which generates a current and delivers energy

111
Q

Electromotive force

A

Describes the electrochemical cell, if the emf is positive, the cell is spontaneous

Ecell = Ered,cathode - Ered,anode

112
Q

Gibbs free energy of electrochemical cell

A

ΔG* = -nFE*cell where ΔG* is the standard change in free energy, n is the number of moles of electrons exchanged, F is the Faraday constant, and E*cell is the standard emf of the cell

113
Q

Nernst equation

A

Ecell = E*cell - (RT/nF)lnQ

Q = [C]c[D]d / [A]a[B]b

114
Q

Reaction equilibrium equation

A

ΔG* = -RTlnKeq

115
Q

Nomenclature, Aldehydes

A

O=C-H

indicated with the suffix -al or the prefix oxo- when not the highest priority group

116
Q

Nomenclature, Ketones

A

R-(C=O)-R

indicated with the suffix -one

117
Q

Nomenclature, Esters

A

O=C-OR

indicated with the suffix -oate

118
Q

Nomenclature, Amides

A

O=C-N indicated with the suffix

-amide

119
Q

Nomenclature, Anhydrides

A

O=C-O-C=O indicated with the suffix

-anhydride

120
Q

Nomenclature, Imine

A

C=N

121
Q

Nomenclature, Enamine

A

C=C-N

122
Q

Nomenclature, Cyanohydrins

A

HO-C-Cn

123
Q

Nomenclature, Aldol

A

O=C-C-C-OH aldehyde plus alcohol

124
Q

Conformational vs configurational isomers

A

Conformational isomers differ in rotation, Configurational isomers require bond breaking to interconvert (enantiomers and diastereomers)

125
Q

Newman projection different conformations

A

eclipsed

staggered

  • anti - two largest groups are on opposite sides
  • gauche - two largest groups are 60* apart
126
Q

Enantiomers

A

Enantiomers differ at all chiral centers

when present in equal concentrations they form racemic mixtures, which can be separated with a single enantiomer of another compound, leading to two diastereomers

127
Q

Diastereomers

A

Cis-Trans molecules

differ in arrangment around an immoveable bon

128
Q

Cylic conformations and ring strain factors

A

Cyclic conformations can be either stable or unstable depending on ring strain

Angle strain bond angles deviate from their ideal values

Torsional strain cyclic molecules are eclipsed or gauche

Nonbonded strain (van der waals repulsion) nonadjacent atoms or groups compete for the same space

129
Q

Meso compounds

A

a molecule with at least 2 chiral centers that has an internal plane of symmetry

130
Q

(E) and (Z) form

A

polysubstituted double bonds

Z if the highest priority (atomic number) are on the same side, E if opposite

131
Q

(R) and (S) forms

A

highest atomic number is highest priority

clockwise is R where counterclockwise is L

switch if the lowest priority is in front of molecule (wedge in Fischer, side in skeleton)

132
Q

bond strength/acidity and periodic table

A

acidity increases towards the bottom right of the periodic table

133
Q

Nucleophiles

A

either lone pairs or pi bonds that can form new bonds to electrophiles

determined by four major factors

134
Q

Four factors of nucleophilicity

A

Charge - nucleophilicity increases with electron density / negative charge

Electronegativity - nucleophilicity decreases as electronegativity increase because these atoms are less likely to share electron density

Steric hindrance - bulkier molecules are less nucleophilic

Solvent - protic solvents can hinder nucleophilicity by protonation of the nucleophile or through hydrogen bonding

For protic solvents, nucleophilicity goes I- > Br- > Cl- > F-

For aprotic solvents, nucleophilicity goes I- < Br- < Cl- < F-

135
Q

Nucleophilic Substitutions SN1 description and rate determination

A

Unimolecular, contain two steps

rate of the reaction depends only on the concentration of the substrate rate = k[R-L], where R-L is an alkyl group containing a leaving group

136
Q

Nucleophilic Substitutions SN2 description and rate determination and special considerations

A

Bimolecular, contain only one step

rate of the reaction depends on both the concentration of the substrate and the nucleophile

rate = k[R-L][Nu:]

nucleophile must be strong and the substrate cannot be sterically hindered

accompanied by an inversion of relative configuration, the position of the substituents around the substrate carbon will be inverted (R -> S or vice versa)

137
Q

Where will a redox reagent preferably act

A

A redox reagent will tend to act on the highest priority functional group

138
Q

Phenol nomenclature

A

adjacent carbons are called ortho, separated by a carbon is called meta, opposite sides is called para

139
Q

Alcohol oxidation reactions (Primary and secondary)

A

Primary alcohols can be oxidized to aldehydes

-only be PCC, a mild oxidant

Primary alcohols can be oxidized past aldehydes to geminal (same carbon) diols to carboxylic acid

-with stronger oxidizing agents than PCC

Secondary alcohols can be oxidized to ketones with any oxidizing agent

Tertiary alcohols cannot be oxidized

140
Q

Mesylates and tosylates

A

Mesylate have the functional group -SO3CH3

Tosylates contain the functional group -SO3-C6H4(benzene)-CH3

these groups can serve as protecting groups or can be formed from alcohols to make better leaving groups

141
Q

Quinones and hydroxyquinones

A

Treatment of phenols with oxidizing agents produces quinones (O=ring) example of secondary alcohol oxidation

not necessarily aromatic because they lack the conjugated ring structure

Hydroxyquinones share the same ring and carbonyl backbone as well as a hydroxyl group

Ubiquinone (CoQ) is a biologically active quinone

142
Q

Aldehydes and Ketones- Hydration

A

In the presence of water, aldehydes and ketones react to form geminal diols (same carbon diols)

-the reaction rate can be increased by adding a small amount of catalytic acid or base

143
Q

Acetal or ketal formation

A

Acetals C-(OR-)C(-OR)-H or ketals C-(OR-)C(-OR)-C can be created with the reaction of aldehydes or ketones with two equivalents of alcohol or a diol catalyzed by anhydrous acid

144
Q

Hemiacetal or hemiketal formation

A

Hemiacetals C-(OR-)C(-OH)-H or hemiketals C-(OR-)C(-OH)-C can be created with the reaction of aldehydes or ketones with one equivalent of alcohol

endpoint in basic conditions

145
Q

Imines and enamines formation

A

Simplest case of imine formation from aldehyde/ketone:

-ammonia adds to the carbon and water is lost

–examples of a condensation reaction and nucleophilic substitution

Imines can tautomerize to enamines

146
Q

Cyanohydrin formation

A

HCN + aldehydes or ketones can create cyanohydrins, as the CN group adds to the carbonyl carbon and forces reduction

147
Q

Oxidation of aldehydes

A

Aldehydes can be oxidized to carboxylic acids with any oxidizing agent stronger than PCC

148
Q

Aldehyde and ketone reduction by hydride reagents

A

Aldehydes and ketones can be reduced to form alcohols

-most often performed with the hydride reagents LiALH4 and NaBH4

149
Q

Keto-Enol tautomerization

A

the enol is named for its C=C and -OH the two isomers are called tautomers, and interconvert through tautomerization/enolization

the thermodynamic intermediate is most stably substituted but forms less quickly

Enamines are tautomers of imines in the same way

150
Q

Aldol condensation

A

An aldehyde or ketone acts as both an electrophile (in keto form) and a nucleophile (in enolate form), and the end result is a formation of a carbon-carbon bond from a beta carbon to an alpha carbon

-requires a catalytic amount of base

Aldol has a carbonyl and a hydroxyl group sharing a beta carbon

-aldehyde and alcohol = aldol

An example of a condensation reaction and a dehydration reaction because two molecules are joined with the loss of a small molecule

151
Q

Retro-aldol reaction

A

reverse of aldol condensation, aqueous base (OH-) is added and heat is applied

152
Q

Carboxylic Acid varying acidity

A

Groups like -NO2 or halides are electron withdrawing and increase acidity

-Dicarboxylic acids are therefore more acidic than analogous monocarboxylic acids due

–beta-dicarboxylic acids have high acidity of the alpha-carbon that they share, although not as high as the hydroxyl hydrogens

Groups like -NH2 or -OCH3 are electron donating and decrease the acidity

153
Q

Carboxyl Acid Synthesis

A

As described above, oxidation of aldehydes and primary alcohols with strong oxidizing agents ((N)Cr2O7, CrO3, KMnO4)

154
Q

Nucleophilic acyl substitution of carboxylic acid

A

Nucleophile- can add to carboxylic acid and substitute for -OH while donating a proton

Different than aldehydes or ketones because those participate in addition

Weak bases (Conjugate bases of strong acids) make good leaving groups

155
Q

carboxylic acid + amine

A

Amides

  • Carboxylic acids can be converted into amides with the addition of an amine in an acidic or basic solution
  • Amides that are cyclic are called lactams and replace -oic with -lactam
156
Q

carboxylic acid + alcohol; nomeclature if product is cyclic

A

A reaction of carboxylic acids with alcohol under acidic conditions results in formation of an ester, with the R- of the ester replacing the -H of the carboxylic acid’s hydroxyl group

  • occurs most rapidly with primary alcohols
  • in acidic conditions

Condensation reaction with water side product

Esters that are cyclic are called lactones and replace -oic with -lactone

157
Q

carboxylic acid + carboxylic acid

A

Anhydrides can be formed by the condensation of two carboxylic acids

158
Q

Carboxylic acid reduction

A

Carboxylic acids can be reduced to primary alcohols by the use of LiALH4

159
Q

Decarboxylation

A

beta-keto acids like 1,3-dicarboxylic acids may spontaneously decarboxylate when heated

160
Q

Saponification

A

Long chain carboxylic acids reacted with sodium or potassium hydroxide to create a salt (H of the hydroxyl is replaced with Na or K)

Know the product as soap

161
Q

Carboxylic acid derivates

A

Amides, Esters and Anhydrides are all formed by a condensation reaction with a carboxylic acid

162
Q

Amide synthesis

A

synthesized by reaction of other carboxylic acid derivatives with either ammonia or an amine

163
Q

Ester synthesis

A

dehydration synthesis products of other carboxylic acid derivatives and alcohols

164
Q

Fischer esterification

A

Under acidic conditions, mixtures of carboxylic acids and alcohols will condense into esters with the R replacing the H of the hydroxyl group

165
Q

Anhydride synthesis

A

condensation dimers of carboxylic acids, wherein the oxygen of one carboxylic acids hydroxyl group bonds to the alpha carbon of another

166
Q

Relative reactivity of carboxylic acid derivatives

A

Anhydrides are most reactive, followed by esters (tied with carboxylic acids although they usually have lower boiling points) and then amides

167
Q

Strain in cyclic derivatives of carboxylic acids

A

certain times lactams and lactones are more reactive to hydrolysis because they contain more strain

four membered rings have torsional strain from eclipsing interactions and angle strain from not having a 109.5* angle

168
Q

anhydride cleavage

A

Addition of a nucleophile to an anhydride results in carboxylic acid derivative and carboxylic acid

-derivative depends on nucleophile; if amine the derivative is an amide

169
Q

transesterification

A

Alcohols can act as nucleophiles and displace the esterifying group on an ester, transforming one alcohol for another

170
Q

Amide hydrolysis

A

Amides can be hydrolyzed under highly acid conditions via nucleophilic substitution, replacing an -NH2 with a -OH from water

171
Q

Strecker synthesis

A

generates an amino acid from an aldehyde

An aldehyde is mixed with ammonium chloride (NH4Cl) and potassium cyanide.

The ammonia attacks the carbonyl carbon, generating an imine.

The imine is attacked by the cyanide, generating an aminonitrile

The aminonitrile is hydrolyzed by two equivalents of water, generating an amino acid

172
Q

Gabriel synthesis

A

generates an amino acid from potassium phthalimide, diethyl bromomalonate, and an alkyl halide

phthalimide attacks the diethyl bromomalonate, generating a phthalimid-omalonic ester

The phtalimidiomalongic ester attacks an alkyl halide, adding an alkyl group to the ester

The product is hydrolyzed, creating phthalic acid and converting the esters into carboxylic acids

One carboxylic acid of the resulting 1,3-dicarbonyl is removed by decarboxylation

173
Q

IR spectroscopy; fingerprint area, hydroxyl area, carboxylic acid area, aldehyde/ketone area, amine

A

fingerprint region of 1500 to 400 cm-1

Hydroxyl group at 3300 for alcohols, 3000 for carboxylic acids with broad peak

carbonyl at 1700 with sharp deep peak (aldehydes and ketones)

NH bonds at 3300 with sharp peak

174
Q

UV spectroscopy

A

never have to interpret but is obtained by passing light through a sample and recording the absorbance

175
Q

NMR spectroscopy, which direction is downfield what affect do electronegative atoms have what is height and number of peaks proportional to

A

left is downfield and increasing chemical shift TMS is marked at 0, ignore it

The height of each peak is proportional to the number of protons it contains

electronegative atoms pull electron density downfield

the number of peaks indicates the number of adjacent protons

176
Q

NMR spectroscopy, aldehyde hydrogens, carboxylic acid hydrogen, aromatic hydrogen

A

Aldehyde Hydrogens > 9 to 10 ppm

Carboxylic acids Hydrogens > 10.5 to 12 ppm

Aromatics Hydrogens > 6.0 to 8.5 ppm

177
Q

NMR spectroscopy, sp3 hydrogens, sp2 hydrogens, sp hydrogens

A

sp3 hydrogens -> 0 to 3 ppm

sp2 (alkene) hydrogens -> 5 to 7 ppm

sp hydrogens -> 2 to 3 ppm

178
Q

Extractions

A

have an aqueous phase and a organic phase

once the desired product has been isolated in the solvent, we can obtain the product alone by evaporating the solve, usually with a rotovap

179
Q

Filtrations, gravity vs vacuum

A

isolates a solid (residue) from a liquid (filtrate)

Gravity filtration is used when the product of interest is in the filtrate, hot solvent is used to maintain solubility

Vacuum filtration is used when the product of interest is solid. A vacuum is connected to the flask to pull the solvent through more quickly

180
Q

Distillations, simple vs vacuum vs fractional

A

separates liquids according to their boiling point

Simple distillation if the boiling points are under 150C and are at least 25C apart

Vacuum distillation if the boiling points are over 150C to prevent degradation of the product

Fractional distillation if the boiling points are less than 25C apart because it allows more refined separation of liquids by boiling point

181
Q

Chromatography general principle

A

Use two phases to separate compounds based on physical or chemical properties

the stationary phase or adsorbent is a polar solid

the mobile phase runs through the stationary phase and is usually a liquid or gas

182
Q

TLC and paper chromatography stationary phase and mobile phase

A

TLC and paper chromatography the stationary phase is a polar material, such as silica, alumina, or paper the mobile phase is a nonpolar solvent, which climbs the card through capillary action

183
Q

Reverse phase chromatography

A

need to insert

184
Q

Rf

A

Rf- Retardation factor distance spot moved / distance solvent front moved

185
Q

Column chromatography general principle

A

uses an entire column filled with silica or aluminum beads as an adsorbent

ion exchange chromatography, size exclusion chromatography, affinity chromatography

186
Q

Ion exchange, size exclusion, and affinity chromatography

A

Ion exchange chromatography

the beads are coated with charged substance to bind compounds with opposite charge

Size exclusion chromatography

the beads have small pores which trap smaller compounds and allow larger compounds to travel through faster

Affinity chromatography

the column is made to have high affinity for a compound by coating the beads with a receptor or antibody

187
Q

Gas chromatography

A

separates vaporizable compounds according to how well they adhere to the adsorbent in the column

the stationary phase is a coil of crushed metal or a polymer, the mobile phase is an inert gas

can be combined with mass spectroscopy to ionize the fragments and determine molecular weight or structure

188
Q

HPLC (High performance liquid chromatography)

A

similar to column chromatography but uses sophisticated computer-mediated solvent and temperature gradients

MCAT (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions