Question

Write the chemical reaction whose equilibrium constant is (a) ka for benzoic acid, c6h5co2h (b) kb for benzoate ion, c6h5co 2 (c) kb for aniline, c6h5nh2 (d) ka for anilinium ion, c6h5nh 3

Answer 1

a) Ka for benzoic acid, C6H5CO2H 
HA + H2O ⇋ A^- + H3O^+ 
Ka = [A^-][H3O^+] / [HA] 
C6H5CO2H + H2O ⇋ C6H5CO2^-^- + H3O^+ 
Ka = [C6H5CO2^-][H3O^+] / [C6H5CO2H] 

b) Kb for benzoate ion, (C6H3CO2)^ - 
B + H2O ⇋ [BH]^+ + OH^- 
Kb = [[BH]^+][OH^-] / [B] 
C6H3CO2^- + H2O ⇋ C6H5CO2H + OH^- 
Kb = [C6H5CO2H][OH^-] / [C6H3CO2^-] 

c) Kb for amiline, C6H5NH2 amiline? aniline 
C6H5NH2 + H2O ⇋ [C6H5NH3]^+ + OH^- 
Kb = [[C6H5NH3]^+][OH^-] / [C6H5NH2] 

d)Ka for amilimium ion, (C6H5NH3)^+ 
C6H5NH3^+ + H2O ⇋ C6H5NH2 + H3O^+ 
Ka = [C6H5NH2][H3O^+] / [C6H5NH3^+]