Weak Acids
351
TABLE 23-1
\
lonization Constants at 25 C
Name
Weak acids
Acetic acid
Boric acid
Carbonic acid
Cyanic acid
Formic acid
Hydrazoic acid
Hydrocyanic acid
Hydrofluoric acid
Hydrogen sulfide
Nitrous acid
Oxalic acid
Phosphoric acid
Phosphorous acid
Bisulfate ion
Sulfurous acid
Weak bases
Ammonia
Methylamme
Ethylamme
Dimethylamme
Tnmethylamme
Aniline
Pyridme
Water
Reaction
HC 2 H 3 O 2 ?±H
+ + C 2 H 3 Of
H 3 BO 3 <=>H
+ + H 2 BC7
H 2 CO 3 ?±H + + HCOj
HCO 3 -?±H
+ + CO§HCNO ?±H
+ + CNOHCHO2*±H
+ + CHC7
HN3*±H
+ + N,
HCN <=»H
+ + CNHF <=»H
+ + FH2S *±H
+ + HSHS- ^±H+ + S
2 -
HNO2^H
+ + NO2H2C2O4*±H
+ + HC2O^
HC2C7^H
+ + C20iH,PO4<^H
+ + H2PO4H2PO4-?±H
+ + HPOJHPOi-^H
+ + POf
H^d^H^ + H2PO3HSOj^H* + SOJH2SO3^H
+ + HSOj
HSOf ?sH
+ + SOjNH3 + H.,0 <±NHf + OHCH3NH2 + H2O <^ CH,NHT + OHC2H5NH2 + H2O f± C2H5NHJ- + OH(CH3)2NH + H2O ?± (CH3)2NHJ + OH(CH3)3N + H20 ^(CHJ^H* + OHC6H5NH2 + H2O f± C6H,NH^ + OH"
C5H5N + H20 ?±C5H5NH
+ ^ OHH20 ?±H
+ + OHK,
^ 74 x 10~
5
589 x 10-'°
K, = 447 x 10'
7
K2 = 468 x 10-"
2 19 x 101
1 70 x 10-"
1 91 x 10-'
631 x 10-'°
676 x 10"
4
K, = 1 00 x 10-'
K2 = 1 20 x 10-'
J
5 13 x 10-"
K! = 562 x 102
K2 = 525 x 105
K, = 589 x 103
K2 = 6 17 x 10-"
K, = 479 x 10-'
J
K, = 1 00 x 102
K2 = 1 02 x 10^K! = 1 74 x 10~
2
K2 = 6 17 x 10-"
1 74 x 10-'
459 x 10-"
500 x 10-"
581 x -\0-*
611 x 10-'
4 17 x 10-'°
1 48 x 10~
9
1 00 x 10-'
4
PROBLEM:
What is the pH of a 0.0500 M acetic acid solution
9
SOLUTION:
Write the chemical equation, and above each term of the equation write the
equilibnum molar concentration. Because we are not given the H
+ and C 2 H 3 O2~