really 9o10nizatioln 11 If a 0100 M solution of a weak base

(really 9o-10nizatioln) 11) If a 0.100 M solution of a weak base is 2.34% ionized, what is the Kb and pKb for this base. What is the pKa of its conjugate acid?

Solution

For weak base,

% of ionization = sqrt (Kb / C) * 100

2.34 = sqrt(Kb / 0.100) * 100

Kb = 5.48 * 10^-5

PKb = -log Kb = -log (5.48 * 10^-5) = 4.26

PKb = 4.26

PKa + PKb = 14

PKa = 14 - 4.26

PKa = 9.74