Ionization Constants for Weak Bases

 

Base

Ionization Equation

Kb

ammonia

NH3 + H2O NH4+ + OH-

 1.8 x 10-5

aniline

C6H5NH2 + H2O C6H5NH3+ + OH-

 4.2 x 10-10

dimethylamine

(CH3)2NH + H2O (CH3)2NH2+ + OH-

 7.4 x 10-4

ethylamine

C2H5NH2 + H2O C2H5NH3+ + OH-

 6.4 x 10-4

ethylenediamine

(CH2)2(NH2)2 + H2O (CH2)2(NH2)2H+ + OH-

 Kb1 = 8.5 x 10-5

 

(CH2)2(NH2)2H+ + H2O (CH2)2(NH2)2H22+ + OH-

 Kb2 = 2.7 x 10-8

hydrazine

N2H4 + H2O N2H5+ + OH-

 Kb1 = 8.5 x 10-7

 

N2H5+ + H2O N2H62+ + OH-

 Kb2 = 8.9 x 10-16

hydroxylamine

HONH2 + H2O HONH3+ + OH-

 6.6 x 10-9

methylamine

CH3NH2 + H2O CH3NH3+ + OH-

 5.0 x 10-4

pyridine

C5H5N + H2O C5H5NH+ + OH-

 1.5 x 10-9

trimethylamine

(CH3)3N + H2O (CH3)3NH+ + OH-

 7.4 x 10-5