

Kb = 4.27 x 10-10
Concentration (c) = 0.001 M
Kb = ca2
4.27 x 10-10 = 0.001 x a2
a2 = 4.27 x 10-10 / 0.001 = 4270 x 10-10
a = 6.53 x 10-5
Then, anion = ca = 0.001 x 6.53 x 10-4 = 0.065 x 10-5
pOH = -log [0.065 x 10-5] = 6.18
pH = 14 - 6.18 = 7.82
Now, Ka x Kb = Kw
Ka x = 4.27 x 10-10 = 10-14
Ka = 10-14/4.27 x 10-10 = 2.34 x 10-5
