J.R. S. answered 10/19/23
Ph.D. University Professor with 10+ years Tutoring Experience
We must look at the hydrolysis of the base, B:
B + H2O ==> BH+ + OH-
Kb = [BH+][OH-] / [B]
6.62x10-3 = (x)(x) / 1.35 - x
6.62x10-3 = x2 / 1.35 - x
x2 + 6.62x10-3 - 8.94x10-3 = 0
x = 0.0913 = [OH-]
Percent ionization = [OH-] / [B]
% = 0.0913 M / 1.35 M (x100%) = 6.76% ionized