Chem 112 EXAM 2 dr. kriley GCC

how to find pOH?

pOH = -log [OH-]

how to find pH?

pH = -log [H+]

Ka of acetic acid

Ka = 1.8 × 10^-5

hydrogen and hydroxide combined equation

[H+][OH-] = 1×10^-14 @ 25*C

what is the Ka of a strong acid?

infinity

disassociation of water ions equation

Kw = 1×10^-14 = [H+][OH-]

disassociation of a weak acid equation

Ka = [H+][A-] / [HA-]

buffer equation

Ka = (1+x)(x) / (1-x) = 1.8×10^-5

henderson hasslebach equation

pH = pka + log(A-/HA)

nernst’s equation

E=E*-(0.0592/n) log(p/r)

gibbs free energy equation

$$\Delta G=-nFE$$

how much is 1 faraday?

96,500 coulombs

3rd half cell equation

E*= (n1E1+n2E2) / (n1+n2)

equilibrium constant (combination of gibbs equations) equation

-nFE=-RT ln K

when pH is neutral, what is [H+]?

[H+] = 1×10^-7

WHEN SHOULD YOU identify the ionization of water?

[H3O+] or [H+] < 4.5×10^-7

WHAT EQUATION is used to identify the ionization of water?

$$\left\lbrack H^{+}\right\rbrack total=\sqrt{Ka\left\lbrack HA\right\rbrack+Kw}$$

what is an acid?

proton donor

what is a base?

proton acceptor

amphoteric

something acting as both an acid and a base

example of amphoteric

water

polyprotic acid

can give up more than 1 proton

hydrolysis

separation of compound into 2 products by reacting with H2O

le chatlier’s principle

if a system @ equilibrium is @ stress, it will react in a way to remove that stress

buffer

solution of weak acid: concentration of anion is the same as the concentration of the undissolved acid, has a pH = pKa of the solid

molar solubility

number of moles of substance that dissolves / liter of solution

electrolytic cell

electrical E from external source that causes a nonspontaneous reaction

galvanic cell

produces own E from spontaneous reaction

cell reaction

sum of 2 half reactions

electromotive force

driving force of cell reaction

cell potential

measured difference between each ½ cell to gain or lose e-

faraday’s law (definition)

charge @ cathode determines the # e- needed to produce 1 anode ion

gibbs free energy (definition)

amount of energy needed to do work

in the bronstead concept, if [H+] = [OH-], what is the solution (neutral, acidic, basic)?

neutral

in the bronstead concept, if [H+] > [OH-], what is the solution (neutral, acidic, basic)?

acidic

in the bronstead concept, if [H+] < [OH-], what is the solution (neutral, acidic, basic)?

basic

what do weak acids form (strong or weak conjugate bases)?

strong conjugate bases

in an equation, how do you determine if it is a weak acid or strong acid?

weak acids use a double-sided arrow, and strong acids use one-sided arrow

what do strong acids form (strong or weak conjugate bases)?

weak conjugate base

what does a strong acid and weak base create when mixed together?

acidic solution

what does a strong base and weak acid create when mixed together?

basic solution

can buffers withstand the addition of large amounts of an acid or base? (Y/N)

no

weak acid ratio

H3O/Ka as close to 1 as possible

weak base ratio

OH/Kb as close to 1 as possible

in solubility products, what is the saturation of [P1][P2] < Ksp (unsaturated, saturated, solid would be present)

unsaturated

in solubility products, what is the saturation of [P1][P2] = Ksp (unsaturated, saturated, solid would be present)

saturated

in solubility products, what is the saturation of [P1][P2] > Ksp (unsaturated, saturated, solid would be present)

solid would be present

what is the result of adding a common ion?

decrease of a solubility of a salt

standard state of a solution

1M

standard state of a gas

1 atm

for $\Delta G$ to be spontaneous, what should E be?

positive