Acid lonization Constants (K,) for Some Monoprotic Weak Acids at 25 ec s Formula Structural Formula lonization Reaction HCIO2 Chlorous acid 1.96 Ho (aq)CO2 (aq) Go(g) 1.110 Nitrous acicd HNO2 HNO2(aq) H20(,) H0 (aq)NO2 (aq) + 4.6 10 3.34 Hydrofluoric acid HF HF(ag) H200 H-F 3.5 104 3.46 H0 (aq)F(aq) Formic acid ????? HCHO2(ag)H200) - 3,74 H-0-C-H Ho (ag)CHO2 (aq) CHO g)1.8 101 ?? ? HC7H502 CH HC,H02(a)H20U) H-0-C-C Benzoic acid 6.510 4.19 H0 (a) C,MG02 (a0) HC,H30(aq) H20U) Acetic acid 1.8 x 10 4.74 H-0-C-CH H30 (aq) CH02 (aq) HOO(aq) H20(,) H30 (aq) = + 2.9 x 10 7.54 Hypochlorous acid HCIO CIO (aq) HCN(ag) H20U) 9.31 HCN Ho (aq)CN CN (ag)4.9 10 1 acid HC@H,0(aq) H200)- 1010 9.89 CH 1.3 x Phenol HCgHs0 ??-? H0(aq)CaHO (aq) KkK. (See tha dieeuesinn at the end of Section 15 Solution 1) the given Ka = 3.16 x 10^-5 pKa = -log Ka = -log (3.16 x 10^-5) pKa = 4.50 the corresponding acid = Acetic acid . acetic acid pKa = 4.74 this is very close to the given pKa value. .

1. Acid lonization Constants (K,) for Some Monoprotic Weak Acids at 25 ec s Formula Structural
Formula lonization Reaction HCIO2 Chlorous acid 1.96 Ho (aq)CO2 (aq) Go(g) 1.110 Nitrous
acicd HNO2 HNO2(aq) H20(,) H0 (aq)NO2 (aq) + 4.6 10 3.34 Hydrofluoric acid HF HF(ag)
H200 H-F 3.5 104 3.46 H0 (aq)F(aq) Formic acid ????? HCHO2(ag)H200) - 3,74 H-0-C-H Ho
(ag)CHO2 (aq) CHO g)1.8 101 ?? ? HC7H502 CH HC,H02(a)H20U) H-0-C-C Benzoic acid
6.510 4.19 H0 (a) C,MG02 (a0) HC,H30(aq) H20U) Acetic acid 1.8 x 10 4.74 H-0-C-CH H30
(aq) CH02 (aq) HOO(aq) H20(,) H30 (aq) = + 2.9 x 10 7.54 Hypochlorous acid HCIO CIO (aq)
HCN(ag) H20U) 9.31 HCN Ho (aq)CN CN (ag)4.9 10 1 acid HC@H,0(aq) H200)- 1010 9.89
CH 1.3 x Phenol HCgHs0 ??-? H0(aq)CaHO (aq) KkK. (See tha dieeuesinn at the end of Section
15
Solution
1)
the given Ka = 3.16 x 10^-5
pKa = -log Ka
= -log (3.16 x 10^-5)
pKa = 4.50
the corresponding acid = Acetic acid .
acetic acid pKa = 4.74
this is very close to the given pKa value.