Question

The pH of ${10}^{-5}MNaOH$ aqueous solution at ${25}^{\circ }Cis:$

• A. 7.04
• B. 7
• C. 6.89
• D. 9

Answer 1

Answer: (D)

9

$NaOH$ is a strong elecytrolyte and it completely dissociates.

$\left[NaOH\right]=\left[O{H}^{-}\right]={10}^{-5}$

$pOH$ = $-log\left[OH\right]$ =$-log\left[{10}^{-5}\right]=5.0$

$pH=14.0-POH=14.0-5.0$

$pH=9.0$

Hence,option D is correct answer.