 Acetic
Acid (HC2H3O2) has 0.767%
dissociation in a 0.300M solution at 25°C.
Find the Ka for acetic acid at 25°C and
the solution’s pH
 Acids
that can give up MORE than one H+
ion
 Diprotic—2
H+ ions capable of ionizing
 Triprotic—3 H+ ions capable of ionizing
 **Each
H+ dissociates separately and in a
separate step--• Specific Ka value for each step.
 Ka1
>>> Ka2 generally for these acids
 Most
of the H+ dissociates in the 1st
dissociation.
 **Use
Ka from the 1st dissociation to
calculate [H+] and pH
 2H2CO3
 HCO3-
 H+ + HCO3- (Ka1=4.3x10-7)
 H+ + CO32- (Ka2=4.7x10-11)
 Calculate
the pH of a 0.125M maleic acid
solution.
HOOCCH=CHCOOH + H2O  H3O+ +
HOOCCH=CHCOO- (Ka = 1.2 x 10 -2)
HOOCCH=CHCOO- + H2O  H3O+ +
-OOCCH=CHCOO- (Ka = 4.7 x 10 -7)
 Finish Weak
 Read
Acid/Base Problems—Friday
over lab procedure