Question

The aqueous solution having pH 11 is how many times less basic than aqueous solution having pH 8?Select the proper choice from the given multiple choices.
(A) 3
(B) 30
(C) 300
(D) 1000

Answer 1

answer :- (D)
case 1:- solution with pH = 11
we know, pH + pOH = 14
=> 11 + pOH = 14
=> pOH = 14 - 11 = 3
according Arrhenius concepts ,
pOH = -log[OH–]
3 = -log[OH–] => log[OH–] = -3
[OH–] = 10^-3

case -2 :- solution with pH = 8
so, pOH = 14 - pH = 14 - 8 = 6
therefore, [OH–] = 10^-6

so the solution with pH = 11 is (10^-3/10^-6) 1000 times more basic than the solution with pH = 8.