chem exam 1: equilibrium, acid/base

Psilocybin (MOTD)

psychedelic found in some mushrooms

Equilibrium

point in reaction where (if it can’t go to completion) the concentration of reactants and products are constant *all reactions in closed systems reach equilibrium

Equilibrium constant

Keq= ([C]^c [D]^d) / ([A]^a [B]^b), a calculated value

Reaction quotient

“Q” the experimental value, same formula as Keq but tells direction of reaction

Meaning if Q=K

reaction is at equilibrium

Meaning if Q>K

reaction goes to the left (more reactants being made)

Meaning if Q<K

reaction goes to the right (more products being made)

Real world acid/base applications

biochem (respiration, proton pumps, etc), inorganic (hydrogen gas from H+), environmental (fish need certain pH to live)

Keq/ for strong acid or base

TRICK QUESTION there is none because they fully dissociate

Arrhenius definition

acids are ionic H+ donors, bases are OH- donors

Lewis definition

acids are electron acceptors, bases are electron donors

*bronstead-lowry definition

acids are H+ donors, bases are the acceptors (conjugate acids & bases present)

Salt (MOTD)

ionic crystal lattice structure, can be mined/evaporated from sea/boiled from briney springs, is needed in humans for neuron synapses/muscles/sodium-potassium pump/stomach acid, osmosis removes water from fish packed in it, was shipped along erie canal from syracuse, taxes led to revolution in india and france

Autoionization

process of something (usually water) “reacting” with itself

Strong bases

all hydroxides of group I&II metals

Strong acids

H2SO4, HI, HBr, HNO3, HCl, HClO4

Meaning of a large Ka/Kb

fully dissociates (meaning a stronger A/B)

Ka/Kb calculation rule of thumb

if magnitude is #x10^-4 or smaller, drop the x

Polyprotic acids

have more than 1 proton (multiple H+) → multiple Ka, each Ka gets smaller because it dissociates less each time

Cobalt (Co) (MOTD)

*renewable energy applications, *acts as catalyst to split H2O into O2, also rechargeable batteries, high strength super alloys, magnets

Le chatlier’s

pushes a ⇋ reaction in favor of one side

Non-base

FOR SALTS ONLY,, conjugate base of strong acid, does NOT contribute to pH (solutions of Cl-, I-, Be-, ClO4-, SO4-2 )

Non-acid

FOR SALTS ONLY, conjugate acid of strong base, does NOT contribute to pH (solutions of Na+, Ci+, K+, Be+2, Sr+2, Mg+2, Ba+2, Ca+2)

Rhodium (MOTD)

*used in homogeneous industrial catalysis & catalytic converters, also super expensive, used in automotive 3-way catalysis, historically made acetic acid (used for drug manufacturing and in body)

Common ion effect?

solution of a weak acid & conjugate base?

acid/base reactions that go to completion

SA/SB (pH=7), WA/SB (pH>7 aka basic, use [OH-]=(BoKb)^½)), SA/WB (pH<7 aka acidic, use [H+]=(CaKa)^½)

Neutralization

all reactants have reacted so the pH is of products only

Buffers

prepared with a combo of WA/CB or WB/CA, with pKa that matches target pH, as long as concentration ratios close to the og then the pH doesn’t change much USE HH Eqn (*NEVER STRONG A/B*NEVER (CaKa)^½)*)