Cliffs AP Chemistry, 3rd Edition

Key Concepts

Equations and relationships that you need to know:

• ∆G°= −RTln K= −0.0191 Tlog Kp
  ∆G°<<0, Kis large; ∆G°>>0, Kis very small
  •pKa= −logKa
  HA()aq++H O 21 ()?H O 3 +-()aq A ()aq
  acid base conjugate conjugate
  acid base

[]

[][]

[]

K [][ ]

HA

HO A

HA

HA

a

=^3 +-? +-

BHOBH OH()aq++ 21 ()? +-()aq ()aq

acid base conjugate conjugate

acid base

K

B

BH OH

b=

+ -

6

77

@

AA

• Ka×Kb= 1.0 × 10 –14= Kw= [H+][OH–]
  K= K 1 ×K 2 ×...


• Q= ion product (or reaction quotient) = calculated as Kspexcept using initial
  concentrations
  Q> Ksp, supersaturated solution, precipitate forms until such point that Q= Ksp
  Q< Ksp, unsaturated solution, no precipitate
  Q= Ksp, saturated solution, no precipitate forms


• Henderson-Hasselbalch: pH pKKlog log
  HA

A

p

acid

base

=+aa=+

6

7

6

6

@

A

@

@

• van’t Hoff equation: lnKK^21 =-∆HR TT^1121 -

%

; E

• Clausius-Clapeyron equation: P
  1

ln

P

R

H

TT

2 ∆ vap^11

%=- 21

% %

; E

• Kp= Kc(RT)∆n
  where ∆n= moles gaseous products −moles gaseous reactants

Part II: Specific Topics