The pH of 10–3M mono acidic base, if it is 1% ionised is

α=KbC0⇒Kb=C0α2 ⇒Kb=10-3×10-22=10-7POH of a weak base solution is given by,⇒POH=12PKb-logC0⇒POH=12[7+3]=5PH = 14 – 5 = 9.