Chemistry Test #3

Front 1

Buffer

Back 1

Chemical system that resists pH changes by neutralizing add acid or base
Significant amounts of weak acid/conjugate base or weak base/conjugate acid (more than the added acid/base)

Front 2

Acidosis

Back 2

A condition in which acid affects the equilibrium between hemoglobin and oxygen

Front 3

Common Ion Effect

Back 3

When the conjugate base is already present, it reduces the ionization of the acid, leading to a less acidic (higher pH) solution

Front 4

X is small approximation

Back 4

For a weak acid or weak base, the concentration of it and its conjugate is essentially identical to the initial concentration
Applicable when the initial concentrations are not two dilute and the equilibrium constant is relatively small

Front 5

Stoichiometry calculation

Back 5

Calculate how the addition of adding an acid or base to a buffer changes the relative amounts of acid and conjugate base

Front 6

Equilibrium calculation

Back 6

Calculate the pH based on the new amounts of acid and conjugate base

Front 7

Henderson-Hasselbalch Equation

Back 7

pH=pKa+log([base]/[acid])

Front 8

Buffer Range

Back 8

Lowest effective pH occurs when the base is one-tenth as concentrated as the acid (pH=pKa-1)
Highest pH occurs when the base is ten times as concentrated as the acid (pH=pKa+1)

Front 9

Buffer Capacity

Back 9

Amount of acid or base that you can add to a buffer without causing a large change in pH: increases with increases with increasing absolute concentrations of the buffer components

Front 10

pH at equivalence point of a strong acid-strong base titration

Back 10

7.00

Front 11

[H3O+][OH-]

Back 11

10^-14

Front 12

Ksp

Back 12

[C]^c+[D]^d

Front 13

Molar solubility

Back 13

Solubility in mol/L

Front 14

Effect of pH on solubility

Back 14

Solubility of an ionic compound with a strongly or weakly basic anion increases with increasing acidity (decreasing pH)

Front 15

Q<Ksp

Back 15

Solution is unsaturated and more of the solid can dissolve

Front 16

Q=Ksp

Back 16

Solution is saturated

Front 17

Q>Ksp

Back 17

The solution is supersaturated

Front 18

Group 1

Back 18

(Add 6M HCl) Insoluble chlorides: only form precipitates with Ag, Hg, and Pb

Front 19

Group 2

Back 19

(add H2S, 0.2M HCl) Acid-insoluble sulfides: for precipitates with Cu, Bi, Cd, Pb, Hg, As, Sb, and Sn

Front 20

Group 3

Back 20

(Add OH-) Base-insoluble sulfides and hydroxides: form precipitate with Al, Fe, Cr, Zn, Ni, Co, Mn, Fe

Front 21

Group 4

Back 21

(Add (NH4)2HPO4, NH3) Insoluble phosphates: form precipitates with Ba, Ca, and MgNH4

Front 22

Group 5

Back 22

(Same as Group 4) Alkali metal ions and Na, K, and NH4

Front 23

Complex ion

Back 23

contains a central metal ion bound to one or more ligands--formation is highly favored

Front 24

Ligand

Back 24

neutral molecule or ion that acts as a Lewis base with the central metal ion

Front 25

Solubility of an ionic compound containing a metal cation that forms complex ions

Back 25

Increases in the presence of Lewis bases that complex with the cation

Front 26

Amphoteric

Back 26

Hydroxides that can act as a base or an acid, especially with Al, Cr, Zn, Pb, and Sn

Front 27

Entropy

Back 27

Thermodynamic function that increase with the number of energetically equivalent ways to arrange the components of the system to achieve a particular state

Front 28

Equation for entropy

Back 28

S=klnW (k=the Boltzmann constant=1.38*10^-23, W=the number of energetically equivalent ways to arrange the system)

Front 29

Macrostate

Back 29

Constant when P, V, and T of a closed system are constant, number of Joules of energy in a given space

Front 30

Microstate

Back 30

Exact arrangement within a macrostate, each microstate adds up to a macrostate (Two 2J atoms and one 1J atom+one 3J atom are different microstates within the same macrostate)

Front 31

Second Law of Thermodynamics

Back 31

For any spontaneous process, the energy of the universe increases (∆Suniv>O)

Front 32

State function

Back 32

Value only depends on the state of the system, not how it got there

Front 33

Calculating ∆S

Back 33

∆S=Sfinal-Sinitial

Front 34

Entropy of solid-->liquid-->gas

Back 34

Increases

Front 35

Calculating ∆Suniv

Back 35

∆Suniv=∆Ssys+∆Ssurr

Front 36

Effect of Release of Heat on Entropy

Back 36

Increases entropy of surrounds

Front 37

Units of entropy

Back 37

J/K

Front 38

Entropy as heat given is given off/abosorbed

Back 38

As the temperature outside becomes significantly higher/lower, ∆Ssurr becomes smaller as heat is given off/absorbed, respectively

Front 39

Calculating ∆Ssurr

Back 39

-∆Hsys/T

Front 40

Gibbs Free Energy

Back 40

∆G=∆H-T∆S

Front 41

∆G<0

Back 41

Spontaneous

Front 42

∆G>0

Back 42

Nonspontaneous

Front 43

∆G when ∆H is negative and ∆S is positive

Back 43

∆G<0, the reaction is spontaneous

Front 44

∆G when ∆H is positive and ∆S is negative

Back 44

∆G>0, the reaction is nonspontaneous

Front 45

∆G when ∆H and ∆S are both negative

Back 45

∆G<0 at low temperatures and ∆G>0 at hight temperatures

Front 46

∆G when ∆H and ∆S are both positive

Back 46

∆G>0 at low temperatures and ∆G<0 at high temperatures

Front 47

Calculating ∆S˚rxn

Back 47

∆S˚rxn=S˚products-S˚reactants

Front 48

Third Law of Thermodynamics

Back 48

The entropy of a perfect crystal at absolute 0 is zero

Front 49

Entropy dependence

Back 49

Extensive: depends on the amount of substance

Front 50

S˚as related to molar mass

Back 50

The more massive a noble gas, the greater its entropy at 25˚C

Front 51

S˚ as related to molecular complexity

Back 51

S˚ increases with molecular complexity, overruling molar mass

Front 52

S˚ of dissolution

Back 52

Increases

Front 53

Calculating ∆S˚rxn

Back 53

∆S˚rxn=∑nS˚(products)-∑nS˚(reactants)

Front 54

Calculating ∆G˚rxn

Back 54

∆G˚rxn=∆S˚rxn-T∆S˚rxn=∑n∆G˚formation(products)-∑n∆G˚formation(reactants)

Front 55

∆Grxn under nonstandard conditions

Back 55

∆Grxn=∆G˚rxn+RTlnQ=-RTlnK

Front 56

lnK

Back 56

-(∆H˚rxn(1/T)+∆S˚rxn)/R