Chem 2 Unit 3

what is an acid base

a reaction involving the transfer of hydrogen ions (H⁺) or electron pairs between species

what does H+ represent in acid-base chemistry

a hydrogen ion (proton)

what is the Bronsted-Lowry definition of an acid

a substance that donates a proton

what is the Bronsted-Lowry definition of a base

a substance that accepts a proton (H+)

what is an amphoteric substance

a substance that can act as both an acid and a base (ex: H₂O)

what is a conjugate acid

the species fored when a base gains an H⁺

what is a conjugate base

the species formed when an acid loses an H⁺

what is true about conjugate acid-base pairs

they differ by exactly one H⁺

what does a strong acid do in water

completely ionizes into ions

six strong acids to memorize

HCl, HNO₃, H₂SO₄, HBr, HI, HClO₄

what happens to the conjugate base of a strong acid

is it very weak/ineffective as a base

what are the common strong bases

hydroxides of group 1 and group 2 metals

why are the strong bases strong

they completely dissociate to produce OH^-

general equation for weak acid ionization

HA + H₂O → H₃O⁺ + A^-

what does Ka measure

acid ionization constant (strength of a weak acid)

what does a large Ka mean

stronger acid

what is pKa

pKa = -log(Ka)

relationship between pKa and acid strength

Lower pKa → stronger acid

general equation for a weak base ionization

B + H₂O → BH⁺ + OH

what does Kb measure

strength of a weak base

relationship between Ka and Kb

Ka x Kb = Kw

auto ionization of water equation

H₂O + H₂O → H₃O⁺ + OH^-

what is Kw

water ionization constant

relationship between H₃O⁺ and OH^-

[H₃O⁺][OH^-] = Kw

pH equation

pH = -log[H₃O⁺]

pOH equation

pOH = -log[OH^-]

relationship between pH and pOH

pH + pOH = 14

acidic vs basic pH

pH<7 → acidic

pH>7 → basic

when is a salt solution neutral

when both ions come from strong acids and strong bases

when is a salt solution acidic

when the cation is the conjugate acid of a weak base

when is a salt solution basic

when the anion is the conjugate base of a weak acid

lewis acid definition

electron pair acceptor

lewis base definition

electron pair donor

what is an adduct

the compound formed when a lewis acid and lewis base bond

what is a polyprotic acid

an acid that can donate more than one proton

what happens to Ka values in polyprotic acids

Ka1 > Ka2 > Ka3

pH of a strong acid

-log[acid concentration]

pH of strong base

1. find pOH = -log[OH^-]

2. pH = 14 - pOH

pH of a weak acid

use Ka and an ICE table to find [H₃O⁺]