Kaplan Gen Chem Contd Flashcards
…: the matter that is being observed –> total amount of reactants and products in a chemical rxn
system
…/..: everything outside of the system
surroundings; environment
systems can be characterized by whether or not they can exchange heat or matter with the surroundings
…: can’t exchange heat/matter with the surroundings
…: system can exchange energy but not matter with the surroundings
…: system can exchange both energy and matter with the surroundings
isolated; closed; open
…: when a system experiences a change in one or more of its properties
associated with a change of the … of a system
some are identified by some property that is … throughout the process
process; state; constant
first law of thermo
change in internal energy of the system = …
Q (heat added); W (work done)
… processes: occur when the system’s temp is constant
constant temp implies that the … is constant throughout the process –> temp and … are directly proportional
isothermal; total internal energy; internal energy
isothermal processes appear as a … on a pressure - volume graph –> … is the area under this curve
hyperbolic curve; work
… processes: no heat is exchanged between the system and the environment –> … of the system is constant throughout the process
adiabatic;
thermal energy
adiabatic processes:
simplifies first law to: …
also … on the P-V graph
delta U = - W;
hyperbolic curve
… processes: occur when the pressure of the system is constant
doesnt alter the first law
appears as a … on a P-V graph
isobaric; flat line
isothermal and isobaric processes are common bc it is usually easy to control … and …
temperature; pressure
… (…) processes: no change in volume –> no … is performed bc the gas neither expands nor compresses
isovolumetric; isochoric; work
(isovolumetric processes) first law simplifies to …
… on a P-V graph
delta U = Q (change in internal energy is equal to the heat added to the system)
vertical line
… process: one that can occur by itself without having to be driven by energy from an outside source
will not necessarily happen quickly and may not go to completion
spontaneous
spontaneous processes:
many have very high … and rarely take place
… selectively enhance the rate of certain spontaneous, slow chemical rxns
activation energies;
enzymes
spontaneous processes:
many spontaneous rxns reach … with dynamically stable concs of reactants and products
common method for supplying energy for nonspontaneous rxns by … nonspontaneous rxns to spontaneous ones
equilibrium;
coupling
…: macroscopic properties that describe the system in an equilibrium state
state functions
state functions cannot describe the … –> how the system got to its current equilibrium
useful for comparing one … state to another
process;
equilibrium
state functions:
pathway taken from one equilibrium state to another is described quantitatively by the … functions: most important are … and …
process;
work;
heat
state functions include: ... .. ... ... ... ... ... ...
pressure; density; temperature; volume; enthalpy; internal energy; Gibbs free energy; entropy
while state functions are independent of the …, they aren’t necessarily independent of one another
processes
because systems can be in different equilibrium states at different temperatures and pressures, a set of standard conditions has been defined for measuring enthalpy, entropy, and Gibbs free energy changes of a rxn:
… (… degrees C), … pressure, and … concentrations
298 K; 25;
1 atm;
1 M
standard conditions are NOT standard temperature and pressure, for which the temp is … (… degrees C)
standard conditions are for …, …, and …
STP is for … calculations
273 K; 0;
kinetics; equilibrium; thermodynamics;
ideal gas;
under standard conditions, the most stable form of a substance is called the … of that substance:
standard enthalpy, standard entropy, and standard free energy
standard state
…: graphs that show the standard and nonstandard states of matter for a given substance in an … system, as determined by temps and pressures
phase diagrams; isolated
phase changes are …, and an … fo phases will eventually be reached at any given combo of temp and pressure
reversible; equilibrium
phase equilibria are analogous to the dynamic equilibria of …: concs of reactants and products are … because the rates of the forward and reverse reactions are …
reversible chemical rxns; constant; equal;
the temperature of any substance in any phase is related to the … of the molecules that make up the substance
average KE
in the liquid phase, molecules are relatively free to move around and some of the molecules near the surface may have enough KE to leave the liquid phase and escape into the gaseous phase –> …/…
each time the liquid loses a high-E particle, the temperature of the remaining liquid …
evaporation is an … process for which the heat source is the …
evaporation/vaporization;
decreases;
endothermic;
liquid
boiling: specific type of vaporization that occurs only under certain conditions –> rapid bubbling of the entire liquid with rapid release of the liquid as …
only occurs .. the boiling point and involves vaporization through the entire .. of the liquid
gas particles;
above;
volume
in a covered container, the escaping molecules are trapped above the solution and some are formed back into the liquid phase –> …
facilitated by … temps or … pressures
condensation;
lower; higher
condensation:
… acts on a liquid in a manner similar to that of an actual physical lid
evaporation and condensation can come into
atmospheric pressure;
equilibrium
condensation:
pressure that the gas exerts over the liquid at equilibrium is the … of the liquid
… as temp increases because more molecules have sufficient … to enter the gas phase
vapor pressure;
increases;
KE
boiling point: temp at which the … of the liquid equals the …
vapor pressure; ambient pressure
availability of energy microstates increases as the temperature of the solid increases –> the molecules have greater … and energy …
if enough energy is absorbed, the 3D structure will break down and the atoms will escape into the liquid phase
mobile freedom; disperses
…/…: transition from solid to liquid
melting point
fusion/melting:
…/…/…: from liquid to solid
freezing point
solidification; crystallization; freezing
… solids have distinct precise melting points
crystalline
… solids (glass, plastic, chocolate, candle wax, etc) tend to melt or solidify over a larger range of temps because they have … molecular structures
amorphous;
less ordered
…: solid goes directly into gas phase
sublimation
…: gaseous to solid phase
a device known as a cold finger can cause things to sublime
deposition
phase diagrams: show the temps and pressures at which a substance will be … in a particular phase
thermodynamically stable
lines on a phase diagram: lines of …/…
indicate the … and … values for the equilibria between phases
lines of equilibrium; phase boundaries;
temp; pressure
lines on a phase diagram:
divide the diagram into three regions corresponding to the … and they themselves represent the …
three phases;
phase transformations
in general, gas is found at … temps and .. pressures, the solid phase is found at … temperatures and … pressures, and the liquid phase is found at … temps and … pressures
high; low;
low; high;
moderate; moderate
point on phase diagram at which all three phase boundaries meet is the …
triple point
phase boundary between the liquid and gas phases terminates at the … –> temperature and pressure above which there is no distinction between the phases
critical point
…: densities of gas and liquid become equal and there is no distinction between the two phases
heat of vaporization at this point and at all temps and pressures above the critical point is …
supercritical fluids;
zero
temperature is related to the average kinetic energy of the particles of a substance –> the way we scale how hot or cold something is
average KE of the particles in a substance is related to the … (…) of the substance
thermal energy; enthalpy
most we can say about temperature is that when a substance’s thermal energy increases, its temperature…
cannot say that something that is hot necessarily has a greater thermal energy than something that is cold –> because there is some dependency on …
also increases;
how much substance is present
there is a finite limit to temperature below which nothing can exist –> no temperature below … because at this point, the system would be unable to lose any more heat energy –> …
0 K; absolute zero
..: transfer of energy from one substance to another as a result of their differences in temperature
heat
zeroth law of thermodynamics: implies that objects are in thermal equilibrium only when their … are equal –> heat is a … function: can quantify how much thermal E is transferred between two or more objects due tot heir differences in temps by measuring heat …
temperatures;
process;
transferred
processes in which the system absorbs heat –> … (delta Q …)
processes in which the system releases heat –> … (delta Q …)
endothermic; > 0
exothermic; < 0
unit of heat is the … or … ( 1 cal = … J)
joule; calorie;
4.184
enthalpy: equivalent to … under …
heat (Q); constant pressure
when substances of different temps are brought into thermal contact with one another, energy will move from the … to the … substance
warmer; cooler
…: process of measuring transferred heat –> … and …
calorimetry;
constant-pressure calorimetry;
constant-volume calorimetry
calorimetry:
heat absorbed/released is calculated by: q = …
c is …
mc*delta T
specific heat
specific heat: the amount of energy required to raise the temp of …. of a substance by …
specific heat of liquid water = …
one gram; one degree C
1 cal/g*K
heat capacities: the product of …
mass * specific heat
constant-pressure calorimeter: insulated container covered with a lid with a solution in which a rxn or some physical process is occurring:
… (…) remains constant and the temp can be measured as the reaction progresses
should be sufficient …
incident pressure; atmospheric pressure;
thermal insulation
… calorimeter/… vessel –> constant-volume calorimetry:
no … is done
bomb; decomposition;
work
constant-volume calorimetry
whole calorimeter can be considered … –> delta U system = …
Q system = …
isolated;
- delta U surroundings;
- qsurroundings
when a compound is heated, the temp rises until the melting/boiling point is reached and then remain … as the compound is being converted into the next phase. once that new phase is reached, temps start rising again
phase change reactions do not undergo changes in temp, so q equation can’t be used for these
the added heat is absorbed by the compound of interest as energy to overcome the … between the molecules
constant;
attractive forces
when transitioning at the solid-liquid boundary, the .. .must be used to determine the heat transferred during the phase change –> change in energy will be … because heat must be added, opposite is true from liquid to solid
enthalpy of fusion;
positive
at the liquid gas boundary, … must be used
enthalpy of vaporization
Q = … (phase change equation)
mL
L is latent heat
total amount of heat needed to cross multiple phase boundaries is just the … of the individual phases being crossed
sum
enthalpy is used to express heat changes at … –> … function
change in enthalpy is equal to the heat transferred into or out of the system at …
positive change in enthalpy is …
constant pressure; state;
constant pressure;
endothermic
standard enthalpy of formation of a compound is the enthalpy required to produce … of a compound from its elements in their …
o ΔHf (with degree symbol) of an element in its standard state is …
one mole;
standard states;
zero
standard enthalpy of a reaction, ΔHrxn (with degree symbol): enthalpy change accompanying a … being carried out under …
reaction; standard conditions
∆Hrxn°= …
ΣΔHf,products°- ΣΔHf,reactants°
enthalpy is a property of the
equilibrium state
hess’s law: enthalpy changes of reactions are
additive
enthalpy change for the phase change is called the heat of …
for a phase change rxn, as long as the initial and final states exist at the standard conditions, the … will always equal the …, irrespective of the pathway the process takes
heat of vaporization ;
delta H rxn;
delta H vap
state functions are always …
path independent
Hess’s law applies to any …, including entropy and Gibbs free energy
state function
hess’s law can be expressed in terms of …/… energies –> average E that is required to break a particular type of bond between atoms in the gas phase
bond enthalpies;
bond dissociation energies
hess’s law with bond dissociation energies:
units: …
averages of the … for the same bond in many different compounds
kJ/mol of bonds broken;
bond energies
hess’s law with bond dissociation energies:
∆Hrxn°=…
ΣΔHbonds broken- ΣΔHbonds formed=total energy absorbed-total energy released
…: enthalpy change associated with combustion of a fuel
standard heat of combustion ∆Hcom°
second law of thermodynamics: energy spontaneously disperses from being localized to becoming … if it isn’t hindered from doing so
spread out
…: measure of the spontaneous dispersal of energy at a specific temperature –> how much energy is spread out or how widely spread out energy becomes in a process
entropy
entropy:
delta S = …
Qrev is heat …/… in a reversible process
units: …
Qrev/T;
gained; lost;
J/mol*K
entropy:
when energy is distributed into a system at a given T, entropy …
when energy is distributed out of a system at a given temp, entropy …
work must usually be done to … energy
increases;
decreases;
concentrate
delta S of universe =
delta S of system + delta S of surroundings > 0
entropy is a … function and is pathway …
state; independent
standard entropy change for a reaction:
∆Srxn°= …
ΣΔSf,products°- ΣΔSf,reactants°
change in Gibbs free energy is a measure of change in … and change in … as a system undergoes a process
the change in free energy is the max amount of energy released by a process that is available to …
enthalpy; entropy;
perform useful work
o ΔG = …
ΔH – TΔS
movement toward the equilibrium position is associated with a … in Gibbs free energy –> spontaneous
opposite is true
decrease
if Gibbs free energy is zero, the system is in a state of … and delta H = …
equilibrium;
T * delta S
for an equilbrium between a gas and a solid
G (g) = G (s)
phase changes are … dependent processes
temperature
for a period of time after a reaction begins, the major product will be the one that is produced more quickly as a result of its … –> … control
after sufficient time, assuming the reaction is reversible, the … product will dominate due to its lower …
lower activation energy; kinetic;
thermodynamic; energy value
for standard free energy determinations the concentrations of any solutions are …
1 M
- …: free energy change that occurs when 1 mole of a compound in its standard state is produced from its respective elements in their standard states under standard conditions
o Standard free energy of formation for any element under standard state conditions is …
Standard free energy of formation of a compound; 0
standard free energy of a reaction is the free energy change that occurs when that rxn is carried out under standard state conditions:
∆Grxn°= …
ΣΔGf,products°- ΣΔGf,reactants°
∆Grxn°= …
greater the value of Keq, the more … the value of the natural log –> more … free energy change –> more … rxn
-RTlnKeq;
positive;
negative;
spontaneous
once a reaction begins, the standard state conditions (specifically the …) no longer apply
value of equilibrium constant must be replaced with another number reflective of where the reaction is in its path toward equilibrium
1 M solutions
delta g for a rxn in progress:
∆G_rxn=…
∆G°rxn+RTlnQ=RTln Q/K_eq
delta g for a rxn in progress:
if the ratio of Q/Keq is less than one, the natural log will be … and the free energy change will be … so the reaction will …
if its greater than one, the natural log will be … and it will proceed spontaneously in the … until equilibrium is reached
if the ratio = 1, the reaction is at equilibrium and free energy change is …
negative; negative;' spontaneously proceed forward; positive; reverse direction; 0
… are fluids whose properties tend to be similar regardless of chemical identity
gases
the state of a gas can be defined by …, …, …, and …
pressure;
volume
temperature;
moles (n)
pressure is usually expressed in … or …, or …
the SI unit is …:
1 atm = … mmHg = …. torr = … kPa
atmospheres; millimeters of mercury; torr; pascals; 760; 760; 101.325
many medical devices use the same conceptual design of a barometer to continually monitor blood pressure:
atmospheric pressure creates a downward force on the pool of mercury at the base of the barometer and the mercury in the column exerts an opposing force based on its …
when external air exerts a greater force than the weight of the mercury in the column, the column … when the external air exerts a lower force than the weight of the mercury, the column …
density;
rises;
falls
many medical devices use the same conceptual design of a barometer to continually monitor blood pressure:
height of the column is thus proportional to the … being applied
it’s not only atmospheric pressure that can exert this force (a clinical BP cuff can act in a similar manner)
atmospheric pressure
many processes involving gases take place under standard temp and pressure (STP):
… and …
NOT STANDARD STATE CONDITIONS
237 K; 1 atm
ideal gas: hypothetical gas with molecules that have no … and occupy …
real gases deviate from this behavior at high … (low …) and low …, but many compressed real gases have behaviors close to ideal
intermolecular forces; no volume;
pressures; V;
temperatures
ideal gas law:
…
useful also for determinations of gas density and molar mass
PV = nRT
R is the ideal gas constant: … or …
8.21 * 10-2 Latm/molK or 8.314 J/K*mol
density: ratio of mass per unit volume of a substance –> for gases the units are …
PV = nRT where n = m(mass)/M (molar mass) –> density = m/V = ….
g/L;
PM/RT
a mole of an ideal gas at STP occupies … L
22.4
combined gas law:
… = …
assumes that the number of moles remains constant
P1V1/T1 = P2V2/T2
molar mass of a gas–> M =
(ρ¬stp)(22.4 L/mol)
the first term is the density of the gas at STP
avogadro’s principle: all gases at a constant temp and pressure occupy volumes that are directly proportional to the … present:
… = … or … = …
number of moles of gas;
n/V = k;
n1/V1 = n2/V2
avogadro’s principle:
as the number of moles of gas increases, the volume … in direct proportion
increases
Boyle’s law: for a given gaseous sample at constant temperature, the volume of the gas is inversely proportional to its …:
… or … = …
pressure;
PV = k;
P1V1 = P2V2
Charles’s Law: at constant pressure, the volume of a gas is proportional to its …:
… or …
when V = 0, …
absolute temperature in Kelvins;
V/T = k; V1T1 = V2T2;
T = 0
Gay-Lussac’s Law:
… or …
P/T = k; P1/T1 = P2/T2
when two or more gases that do not chemically interact are found in one vessel, they will behave … of one another
the pressures of each individual gas are the …
independently; partial pressures
dalton’s law of partial pressures: total pressure of a gaseous mixture is the … of the partial pressures of the individual components:
PT = PA + PB …
sum
a gas’s partial pressure is related to its … (..):
PA =
mole fraction; X;
XAPT –> XA = moles of gas A/total moles of gas
at various applied pressures, the concentration of a gas in a liquid increased/decreased –> characteristic of a gas’s …: pressure exerted by evaporated particles above the surface of a liquid
vapor pressure
vapor pressure from the evaporated molecules forces some of the gas back into the liquid phase and equilibrium is reached between … and …
evaporation; condensation
Henry’s Law:
[A] = … or …
kH is henry’s constant and is dependent on the gas’s …
kH * PA;
[A]1/P1 = [A]2/P2 = kH;
identity
henry’s law: ‘
… (…) and … are directly related
solubility; concentration; pressure
… theory explains the behavior of gases
describes ideal gases
kinetic molecular theory
assumptions made in kinetic molecular theory:
gases are made up of particles with volumes that are … compared to container volume
gas atoms/molecules have no …
negligible;
intermolecular attraction/repulsion
assumptions made in kinetic molecular theory:
gas particles are in …, … motion, colliding with other particles and container walls
collisions between any two gas particles are … –> conservation of both … and …
continuous; random;
elastic; momenum; KE
assumptions made in kinetic molecular theory:
average KE of gas particles is proportional to the … and is the … for all gases at a given temperature
absolute temperature in K; same
KE of a gas particle = …
Kb is the Boltzmann constant = …
3/2kbT
1.38 * 10^-23 J/K
speed of an individual gas particle is nearly impossible to define
speeds of gases are defined terms of …
average molecular speed
root-mean-square speed (urms) =
√(3RT/M)
Maxwell-Boltzmann distribution curve shows the distribution of … at a given temperature
bell shaped curve flattens and shifts to … as temp increases, indicating that more molecules are moving at higher speeds
gas particle speeds; ‘
right
…: movement of molecules from high conc to low conc through a medium
diffusion
heavier gases diffuse more slowly than light ones bc they will have differing average speeds –> since all gas particles have the same average KE at the same temp, particles with greater … travel at slower average speeds
mass
Graham’s law: the rates at which two gases diffuse are inversely proportional to the … of their … (r1 and r2 are rates of diffusion):
r1/r2 =
square roots; molar masses;
√(M_2/M_1 )
…: flow of gas particles under pressure from one compartment to another through a small opening
for two gases at the same temperature the rats of this are proportional to the … –> same relationship as for diffusion
effusion; ‘
average speeds
as the pressure of a gas increases, the … pressure is approached and … become increasingly substantial, until the gas condenses into a liquid
condensation;
intermolecular attraction forces
at moderately high pressure, a gas’s V is … than would be predicted by the ideal gas law due to …
less; intermolecular attraction
at extremely high pressures, the size of the particles becomes large relative to the … between them and the gas takes up a larger volume than would be predicted by ideal gas law:
ideal gas law assumes that a gas can be compressed to take up zero volume, but this is not true
distance
at lower temps, the average speed of gas molecules … and … become more significant
decreases; attractive intermolecular forces
as the temp of a gas is reduced toward its condensation pt (…), intermolecular attractions cause the gas to have a … volume than would be predicted by ideal gas law, but at extremely low temps, gases occupy more space than predicted because they cannot be compressed to zero volume
boiling; smaller
Van der Waals equation attempts to correct for deviations from ideal state:
equation: …
A term corrects for the … between molecules –> smaller for small and less … gases and largest for polar molecules
b term corrects for the … of the molecules themselves
(P+ (n^2 a)/V^2 )(V-nb)=nRT
attractive forces;
polarizable;
volume
solutions are … mixtures of two or more substances that combine to form a single phase
homogenous
all solutions are … but not all mixtures are solutions
mixtures
…: what is dissolved
…: component of the solution that remains in the same phase after mixing or the component present in greater quantity –> the dissolving medium
solute;
solvent
…: electrostatic interaction between solute and solvent molecules, aka …
solvation; dissolution
… is when water is the solvent
hydration
solvation:
breaking intermolecular interactions between solute-solute and solvent-solvent and forming intermolecular interactions between …
… when new interactions are stronger than old ones
solute-solvent;
exothermic
solvation:
dissolution of gases into liquids is …
most dissolutions are …
when the strength of new interactions is almost equal to that of the original interactions the overall enthalpy change is about … –> formation of an …
exothermic;
endothermic;
0;
ideal solution
entropy always … upon dissolution
increases
entropy can be considered the number of … available to a system at a given temp
energy microstates
…: the max amount of that substance that can be dissolved in a particular solvent at a given temp
solubility
…: when maximum amount of solute has been added –> dissolved and undissolved solute states are in …
if more solute is added beyond this point, it won’t dissolve
saturated solution;
equilibrium
…: proportion of solute to solvent is small
a solution where this proportion is large is …
dilute;
concentrated
generally, solutes are considered soluble if they have a molar solubility above … in solution
0.1 M
…: solutes that dissolve minimally in the solvent –> molar solubility ..
sparingly soluble salts;
< 0.1 M
… solution: solute is water
aqueous
(seven general solubility rules for aqueous solutions) all salts containing … and … cations are water-soluble
ammonium; alkali metal cations
(seven general solubility rules for aqueous solutions) ALL SALTS CONTAINING … and … anions are water-soluble
nitrate; acetate
(seven general solubility rules for aqueous solutions)
…, except for …, are water-soluble, except for when they are formed with …, …, and …
halides; fluorides;
Ag+ ; Pb2+; Hg22+
(seven general solubility rules for aqueous solutions) all salts of the … ion are water soluble (…), except for those formed with …, …, …, and …
sulfate; SO4 2-;
Ca2+; Sr2+;
Ba2+; Pb2+
(seven general solubility rules for aqueous solutions) all … are insoluble except for those formed with …, …, …, …, and …, which hydrolyze to form solutions of the corresponding …
metal oxides; alkali metals; ammonium; CaO; SrO; BaO; metal hydroxides
(seven general solubility rules for aqueous solutions)
all … are insoluble except for those formed with …, …, …, …, and …
alkali metals ammonium; Ca2+; Sr2+' Ba2+
(seven general solubility rules for aqueous solutions) all .. (…),
… (….)
… (…)
and … (…)
are insoluble , except for those formed with the … and …
carbonates; CO32-; phosphates; PO4 3-; sulfides; S2-; sulfites; SO3 2- alkali metals; ammonium
… compound: a molecule in which a cation is bonded to at least one electron donor
complex ion/ coordination compound
complex ion/coordination compound:
…: electron pair donor molecules
… rxn
ligands;
complexation
complexes are held together with … bonds –> an electron pair donor and electron pair acceptor form very stable … adducts
important in … including proteins
coordinate covalent;
Lewis acid-base;
macromolecules
..: in some complexes, the central cation can be bonded to the same ligand in multiple places
tends to require … ligands
chelation;
large organic
…: the amount of solute dissolve din a solvent
concentration
percent composition by mass: … * 100%
mass of solute/mass of solution
mole fraction (X) = .../... sum of mole fractions in a system will always be ...
moles of A; total moles of all species;
1
molarity (M): …
mol of solute/ liter of solution
molality (italicized m): …/…
for dilute aqueous solutions at 25 degrees C, the molality is almost equal to … because density of water at this temperature is …
important for boiling pt elevation and freezing point depression
moles of solute/kg of solvent;
molarity;
1 kg/L
normality of a solution is equal to the number of … of interest per … of solution
equivalents;
liter
an equivalent is a measure of the … of a molecule
reactive capacity
relationship between molarity and volume:
MiVi = MfVf
…: equilibrium in the process of creating a solution, where the solute concentration is at its pax value for the given temp and pressure
saturation point
at saturation, equilbirium is established between … of the solute and … of the solute
dissolution;
precipitation
for a saturated solution of an ionic compound with the formula AmBn ⇌ mAn+ + nBm-
the equilbrium constant for its solubility in aqueous solution (the solubility product constant, Ksp), can be expressed by:
Ksp = …
Ksps never have denominators because dissociation rxns by definition have a solid salt as a reactant, and … and … do not appear in the equilibrium constant
= [An+]m[Bm-]n;
solids; liquids
solubility product constants are … dependent. for gases dissolved into a liquid it will also depend on …
temperature; pressure
… (IP): analogous to reaction quotient, Q, for other chemical rxns –> has same formula as Ksp can be used to show where the solution is with respect to the …
ion product;
equilibrium position
ion product:
IP < Ksp –> .., … is favored over …
IP = Ksp –> …; solution at …
IP > Ksp –> …, … is favored over ….
unsaturated; dissolution; precipitation;
saturated; equilibrium;
supersaturated; precipitation; dissolution
…: molarity of a solute in a saturated solution
molar solubility
formation of complex ions increases the … of a salt in solution
have very high … values
solubility;
Ksp
every sparingly soluble salt of general formula MX will have Ksp = …, where x is the molar solubility, formula MX2 will have Ksp = …, formula MX3 will have Ksp = … –> assuming no common ion effect
x^2;
4x^3;
27x^4
Kf –> …/… constant of complex ion in solution
formation; stability
the initial … is the rate-limiting step of complex ion formation
dissolution of the metal ion
solubility of a salt is reduced when it is dissolved in a solution that already contains one of its … as compared to tis solubility in a pure solvent –> …
constituent ions;
common ion effect
presence of common ion has no effect on the … itself
solubility product constant
…: physical properties of solutions that are dependent on the concentration of dissolved particles but not on their chemical identity
colligative properties
colligative properties: ... ... ... ... usually associated with ... solutions
vapor pressure depression; boiling point elevation; ' freezing point depression; osmotic pressure; dilute
Raoult’s law accounts for vapor pressure depression:
as solute is added to a solvent, the vapor pressure of the solvent … –> presence of the solute molecules can block the … of solvent molecules but not their …, …
decreases proportionally;
evaporation;
condensation;
vapor pressure
Raoult’s law:
Pa = …
PA° is the vapor pressure in its … state
XAPA°;
pure
Raoult’s law:
this law holds true only when the attraction between the molecules of the different components of the mixture is equal to the attraction between the molecules of … –> solutions that obey Raoult’s law are …
any one component in its pure state;
ideal solutions
vapor pressure depression means that a …. is required to match atmospheric pressure, thereby raising the …
higher temperature; boiling point
vapor pressure depression:
the extent to which the boiling point is raised relative to the pure solvent: …. –>
i is the … factor, Kb is a proportionality constant characteristic of a particular solvent, and m is the molality of the solution
T_b=iK_b m;
van’t Hoff factor
the presence of solute particles in a solution interferes with the formation of the … of solvent molecules associated with the solid state –> more E must be … in order for the solution to solidify:
…
lattice arrangement;
removed;
∆T_f=iK_f m
osmotic pressure refers to a “sucking” pressure generated by solutions in which … is drawn into a solution:
equation: …
water moves in the direction of … concentration
water;
Π=iMRT
higher solute;
…: dissociates to form excess of H+ in solution
arrhenius acid
…: dissociates to form excess of OH- in solution
arrhenius base
arrhenius acids and bases are limited to those that are …
aqueous
Bronsted-Lowry acid donates … and Bronsted base …
not limited to … solutions
protons;
accepts protons;
aquous
only difference between arrhenius and bronsted acids is that arrhenius requires an … medium and, in arrhenius definition, … is not acidic because it doesn’t produce excess protons in solution, but it is acidic according to Bronsted
aqueous;
water
…: accept electron pair
…: donate electron pair
lewis acids;
lewis bases
lewis acid-base chemistry can be called … formation, … formation, or … interactions
coordinate covalent bond; complex ion; nucleophile-electrophile
lewis acids are often used as …
catalysts
… species: reacts like an acid in a basic environment and like a base in an acidic environment
amphoteric
amphoteric species:
in bronsted sense, amphoteric species can either gain or lose a proton, making it …
partially dissociated conjugate base of a … is usually amphoteric
… of some metals (e.g. Al, Zn, Pb, and Cr) are also amphoteric
amphiprotic;
polyvalent acid;
hydroxides
species that can act as both … and … agents are often considered amphoteric bc they can act as … and …
oxidizing; reducing;
Lewis acids; bases
acids formed from anions with the ending -ide have the prefix … and the ending …
hydro-; -ic
acids formed from oxyanions are …
if the anion ends in -ite, the acid will end with …
if the anion ends in -ate the acid will end with …
oxyacids;
- ous acid;
- ic acid
water can react with itself in an … rxn in which hydronium and hydroxide is produced
endothermic autoionization
autoionization of water is a … rxn
water dissociation constant: Kw = …
reversible;
[H3O+][OH-] = 10-14 at 298
each mol of water that autoionizes produces one mole of … and … so the concs of these are always equal in pure water at equilibrium. the concs of each of the ions in pure water at equilibrium at 298 K is … M
hydrogen ions; hydroxide ions;
10^-7
the product of the concentrations of the hydrogen ions and the hydroxide ions in an aqueous solution at 298 K must always equal …
10^-14
pH = ... = ... pOH = ... = ...
- log[H+] = log(1/[H+]);
- log[OH-] = log(1/[OH-])
…: the negative logarithm of the number of items
p scale;
pH + pOH = … for all aqueous solutions at 298 K
14
if the nonlogarithmic value is written in proper scientific notation, it will be in the form …, where n is a number between 1 and 10. taking the negative log and simplifying the p value will be:
– log (n * 10-m) = -log(n) – log (10-m) = …
Because n is between 1 and 10, the log will be a decimal between … and .., and the closer n is to 1 the closer the log will be to …
the closer n is to 10 the closer the log will be to …
P is approximately …
n * 10^-m; m – log(n); 0; 1; 0; n; m - 0.n
strong acids and bases dissociate … in solution:
if the conc of acid/base is close to 10^-7 M, then the contribution from the … is important
completely;
autoionization of water
some strong acids to remember: ... ... ... ... (...) ... (...) ... (...)
HCl; HBr; HI; H2SO4; sulfuric; HNO3; nitric; HClO4; perchloric
strong bases to remember:
…
…
and other soluble hydroxides of …
NaOH;
KOH;
group I metals
weak acids and bases only … in solution
partially dissociate
a weak monoprotic acid will dissociate only … in water to achieve an equilibrium state
partially
acid dissociation constant:
Ka = …
smaller Ka means the acid is … and will …
Ka = [H3O+][A-]/[HA];
weaker;
dissociate less
Base dissociation constant:
Kb = …
smaller Kb means base is …
Kb = [B+][OH-]/[BOH];
weaker
an acid is weak if its Ka is … and a base is weak if its Kb is …
on the MCAT, molecular weak bases are almost exclusively …
less than 1;
less than 1;
amines
…: acid formed when base gains a proton
…: base formed when acid loses a proton
conjugate acid;
conjugate base
because water is amphoteric, all acid-base reactivity in water ultimately reduces to the …, and all acidic or basic aqueous solutions are governed by the … for water
acid-base behavior of water;
dissociation constant
Ka,acid * Kb, conjugate base = …
Kb,base * Ka, conjugate acid = …
Kw = 10^-14; Kw = 10^-14
Ka and Kb are … related
inversely
conjugate of a strong acid/base is sometimes termed … because it is extremely …
inert; uncreactive
inductive effect by electronegative atoms positioned near an acidic proton … acidity
increases
most common use of acid and base dissociation constants is to determine the … of one of the …
concentration; species in solution at equilibrium
for equilibrium rxn for acids and bases, the approximation of x as small enough to be negligible is valid as long as x is less than … of the initial concentration. typically occurs when Ka is at least … than the concentration of the starting solution
5% of the initial concentration;
100 times smaller
… reactions tend to go to completion. reverse rxn in which … react with water to reform the acid or base is …
neutralization;
salt ions; hydrolysis
products of a reaction between equal concentrations of a strong acid and a strong base are equimolar amounts of … and …
resulting pH is … and is … and the ions formed are … that won’t react with water
salt; water;
neutral; 7;
inert conjugates
the products of a reaction between a strong acid and a weak base is a .., but water usually won’t be formed because weak bases generally aren’t …
cation of the salt is a … that will react with water solvent to re-form some of the weak base
salt;
hydroxides;
weak acid;
pH of a solution containing a weak acid and a weak base depends on the relative ….
strengths of the reactants
in bio and biochem, neutralization reactions are often … rxns because they form bonds with a small molecule as a byproduct
condensation
…: one mole of H+
…: one mole of OH- ions
acid equivalent;
base equivalent
…: each mole of the acid or base liberates more than one acid or base equivalent
under Bronsted definition these are also called …
polyvalent; polyprotic
acidity or basicity of a solution depends on the … that can be liberated
concentration of acidic or basic equivalents
… is the mass of a compound that produces one equivalent
gram equivalent weight
…: procedure used to determine the concentration of a known reactant in a solution
titration
titrations are performed by adding small volumes of a solution of known concentration (…) to a known volume of a solution of unknown concentration (…) until completion of the reaction is achieved at the …
titrant;
titrand;
equivalence point;
in acid-base titrations, the equivalence point is when the … equals the …
equivalents of acid present; number of base equivalents added
equivalence point does not always occur at pH 7, although it will for a … combo
strong acid, strong base
polyprotic acids or bases will show …
multiple equivalence points
… = … –> Na and Nb are the acid and base … and Va an Vb are the volumes of acid and base solutions
NaVa = NbVb; normalities
equivalence point can be measured using a graphical method and plotting the pH of the unknown solution as a function of added titrant by using a … or estimated by watching for a … of an …
pH meter; color change; added indicator
…: weak organic acids or bases that have different colors in their protonated and deprotonated states –> must be … acid or base than the acid or base being titrated so that it is not titrated first
indicators;
weaker
indicators:
can be used in low concs without substantially …
…: the point at which the indicator changes to its final color –> in a good titration with the proper indicator, the … between endpoint and equivalence point should be negligible
altering equivalence point;
endpoint;
volume difference
weak acid/base titrations can be done but are …
inaccurate
for a strong acid strong base combo, in the early part of the curve, … species predominates so addition of small amounts of base will not impact … conc or … substantially. in the last part of the titration curve when an excess of base has been added, the addition of small amounts of base will not change the … significantly
addition of base will have the largest impact near the …
acidic;
hydroxide; pH;
hydroxide ion conc;
equivalence point
if one uses a pH meter to charge the change in pH as a function of volume of titrant added, a good approximation can be made of the equivalence point by locating the … of the region of the curve with the …
midpoint; steepest slope
strong acid + weak base: equivalence point …
strong acid + strong base: equivalence point pH …
weak acid + strong base: equivalence point ..
< 7;
= 7;
pH > 7
the appearance of the titration curve for a weak base titrand and strong acid titrant will look like an … of the curve for a weak acid titrand and strong base titrant
inversion
for weak acid and weak base combo because both the titrant and the titrand are weak, the initial pH is in the … range and will demonstrate a very … drop at the equivalence point equivalence pt will be near … pH because the reaction is partially … for both species
3-11;
shallow;
neutral;
dissociative
to identify which type of titration is being shown in a graph identify the starting position in the graph: pH >> 7 = titrand is a ..., > 7 (slightly) = ... < 7 (slightly) = ... and << 7 pH = ...
strong base;
weak base;
weak acid;
strong acid
the center of the buffer region is sometimes termed the … because it occurs when half of a given species has been …/…
half-equivalence point;
protonated; deprotonated
a buffer solution consists of a mixture of a … and its … or a mixture of a … and its …
can resist changes in pH when small amounts of acid or base are added
weak acid; salt;
weak base; salt
Henderson-Hasselbalch equation:
pH = …
when [A-] = [HA], …, because log (1) = …
buffering capacity is … at this point
pKa + log [A-]/[HA];
pH = pKa;
0;
optimal
Henderson-Hasselbalch equation:
pOH = …
when [B+] = [BOH], …
buffering capacity optimal at this point
pKb + log[B+]/[BOH];
pOH = pKb
if the concentrations of the acid and conjugate base were both increased such that their ratio remained the same, the … would not change but the … would increase
pH;
buffering capacity
buffering capacity is generally maintained within … of the pKa value
…: the ability to which the system can resist changes in pH
1 pH unit;
buffering capacity
…: electrical charge can be neither created nor destroyed
… and …must occur simultaneously
law of conservation of charge; ‘
oxidation; reduction
… causes another atom to be oxidized and is itself reduced
… causes another atom to be reduced and is itself oxidized
oxidizing agent;
reducing agent
almost all oxidizing agents contain … or another … element
oxygen; strongly electronegative
reducing agents often contain … ions or …
metal; hydrides
common oxidizing agents: ... ... ... ... ...
O2; H2O2; halogens H2SO4 HNO3
common oxidizing agents contd: ... ... ..., ... ... ..., ...
NaClO KMnO4 CrO3, Na2Cr2O7 PCC NAD+; FADH
common reducing agents: ... ... ... ... and other ... ...
CO; C; B2H6; Sn2+; pure metals hydrazine;
common reducing agents: ... ... ... ... ..., ...
Zn(Hg); Lindlar's catalyst; NaBH4; LiAlH4; NADH, FADH2
biochemical redox reagents tend to act as both … and … agents at different times during metabolic pathways
oxidizing; reducing
the term oxidizing agent or reducing agent is applied specifically to the atom that … or …
loses; gains electrons
…: assigned to atoms to keep track of the redistribution of electrons during chemical rxns. allows determination of how many … are … by each atom
oxidization numbers; electrons are gained or lost
oxidation number rules:
oxidation number of a free element is …
oxidation number for a monatomic ion is …
0;
equal to its charge
oxidation number rules:
oxidation of each group 1 element in a compound is …
oxidation of each group 2 element in a compound is …
oxidation number of each group 17 element is … except when bonded to an element of higher electronegativity
+1;
+2;
-1
oxidation number rules:
oxidation number of hydrogen is usually … except for when its bonded to less electronegative elements, in which case it is …
in most compounds, the oxidation number of oxygen is … It is … in peroxides
+1;
- 1;
- 2;
- 1
oxidation number rules:
the sum of the oxidation numbers of all the atoms present present in a neutral compound is ….
the sum of the oxidation numbers of the atoms present in a polyatomic ion is equal to the … of the ion
0;
charge
oxidation number assumes … of electrons in bonds, awarding the electrons to the …. element. formal charge assumes … in bonds, awarding one electron to each atom in the bond –> electron density distribution lies between these two extremes
unequal division;
more electronegative;
equal division of electrons;
most common method for balancing redox equations is half-reaction/ion-electron method in which the equation is separated into …
these individual half reactions are … and then …
redox half-reactions;
balanced; added
…: do not participate in the reaction
a reaction can be simplified to the …, removing …
aqueous compounds are split into their … but solid salts should remain a single entity
spectator ions;
net ionic equation; spectator ions;
constituent ions
…/… reactions are not usually redox reactions
double-displacement; metathesis
in double-displacement reactions where both reactants and both products are … there is no …
aqueous; net reaction
… rxns and … rxns in biological systems in general are usually accomplished by enzymes
biochemical disproportionation; redox
redox titrations follow the transfer of … as … to reach the equivalence point
use indicators that change color at a particular … (…) value
charge; electrons;
voltage; emf
…: specific redox titration that uses starch indicators to identify iodine complexes –> relies on the titration of …
iodimetric titration;
free iodine radicals
…: form of redox titration where no indicator is used and the voltage is instead measured using a voltmeter
potentiometric titration
