Question

The pH of 10^-4 M NaOH solution is

(A) 4

(B) 10

(C) 12

(D) 2

Answer 1

Correct option is (B) 10

pOH of a solution is the negative logarithm (where base is 10) of its OH⁻ ion concentration. Therefore,

pOH = -log[OH⁻]

= -log[10^-4]

=  4

We know,

pH + pOH = 14

⇒ pH + 4 = 14

∴ pH = 10

Therefore, the pH of 10^-4 M NaOH solution is 10.