Question

pH of an aqueous $1\times {10}^{-8}MNaOH$ solution is:

• A. 8
• B. 7.02
• C. 7
• D. 6

Answer 1

The correct option is B 7.02

As we know ,

pH = 14 - pOH

The hydroxide ion concentration in neutral water is ${10}^{-7}$

The hydroxide ion concentration in ${10}^{-8}$ M NaOH solution will be ${10}^{-7}+{10}^{-8}={10}^{-7}\times 1.1$

$pOH=-log\left[H^{+}\right]=-log({10}^{-7}\times 1.1)=6.96$

$\therefore$ pH = 14 - 6.96 = 7.04