5 Steps to a 5 AP Chemistry

Equilibrium
Q=reaction quotient

equilibrium constants:
Ka(weak acid) Kb(weak base) Kw(water)
Kp(gas pressure) Kc(molar concentrations)

Kw=[OH−][H+] =1.0 × 10 −^14 =Ka×Kbat 25°C
pH =−log [H+], pOH =−log [OH−]
14 =pH +pOH

pKa=−log Ka, pKb=−log Kb
Kp=Kc(RT)Δn, where Δn=moles product gas −moles reactant gas

Experimental
Beer’s Law: A = abc (A = absorbance; a = molar absorbtivity; b = path length;
c=concentration)

pOH =p

HB

b B]

K +

+

log

[]

[

pH=p

A

a HA]

K +

−

log

[]

[

KKab

HA

HA]

OH H B

B]

==

[][]+− − +

[

[][]

[

Q =

[C] D]

[A] B]

where aA + b B cC + dD

cd

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[

[

, 

Exam Resources  369