Ionic equilibria
Common 10h Effect
Addition of a common icon to an acidlbaseequilibrium will cause it to shift in
order to counter act that addition
consequence limitation on the dissociation of weak acids z bases
Buffer Sola
Functioni resist changes in the pH of a sole when Hz0 1OH are added
Special cage of the common ion
weak acid base corresponding salt of acid base
Characteristics of buffer Sola
Acid base must not neutralize each other
ooo most use acid base conjugate pairs
Contains relatively high amounts of weak acid r conjugate base vice versa
if HzOt is added it will react with the base
if OH acid
pH is determined by the ratio of the concentrations of acid x base
ka EHzotJCAJ.tn EHz0tJCA
I CEHAIo
x CHA o
HzOt CHAI y Ka KaCHAI
A To EA
log HzOt log Ka HgAI logKa logCHAI
CA
pH pKa
, a
I Il
pH pk log CAI Henderson Hasselbakh Equation
HA
Henderson Hasselbatch Equation
buffersole most effective when HA I A j ooo pH pka
A l O o
fo logCHAT log O
80 pH pka
logCAI
CHAY
T pka
criteria
1 0 I EAT 210 2 CA look ka z HA 100X ka
HA
Buffer capacity 2 Range
Buffer capacity i amount of acid base that a buffer can neutralize before its
pH changes appreciably
max buffer capacity exits when HA r CA are larger approximately equal
to each other
Buffer range i the pHrange over which a boffer effectively neutralizes addedacidlbase
Practically range is 2 pH units around pka or pka 11
Is this a buffer
Does it satisfythecriteria Bufferforms from weak
f la acidlbase
Yes No pairs
b t
use HH use stoichiometry
equation a ICE table
Common 10h Effect
Addition of a common icon to an acidlbaseequilibrium will cause it to shift in
order to counter act that addition
consequence limitation on the dissociation of weak acids z bases
Buffer Sola
Functioni resist changes in the pH of a sole when Hz0 1OH are added
Special cage of the common ion
weak acid base corresponding salt of acid base
Characteristics of buffer Sola
Acid base must not neutralize each other
ooo most use acid base conjugate pairs
Contains relatively high amounts of weak acid r conjugate base vice versa
if HzOt is added it will react with the base
if OH acid
pH is determined by the ratio of the concentrations of acid x base
ka EHzotJCAJ.tn EHz0tJCA
I CEHAIo
x CHA o
HzOt CHAI y Ka KaCHAI
A To EA
log HzOt log Ka HgAI logKa logCHAI
CA
pH pKa
, a
I Il
pH pk log CAI Henderson Hasselbakh Equation
HA
Henderson Hasselbatch Equation
buffersole most effective when HA I A j ooo pH pka
A l O o
fo logCHAT log O
80 pH pka
logCAI
CHAY
T pka
criteria
1 0 I EAT 210 2 CA look ka z HA 100X ka
HA
Buffer capacity 2 Range
Buffer capacity i amount of acid base that a buffer can neutralize before its
pH changes appreciably
max buffer capacity exits when HA r CA are larger approximately equal
to each other
Buffer range i the pHrange over which a boffer effectively neutralizes addedacidlbase
Practically range is 2 pH units around pka or pka 11
Is this a buffer
Does it satisfythecriteria Bufferforms from weak
f la acidlbase
Yes No pairs
b t
use HH use stoichiometry
equation a ICE table
