Question

If the pH of solution of NaOH is $12$ pH of $H_{2}S{O}_4$ solution of same molarity will be :

• A. $2.0$
• B. $12.0$
• C. $1.7$
• D. $10.0$

Answer 1

Answer: (C)

$1.7$

For NaOH
$pH=12=\left[H^{+}\right]={10}^{-12}=[oH6-]=\frac{{10}^{-14}}{\left[H^{+}\right]}={10}^{-2}=\left[NaOh\right]$
For $H_{2}S{o}_4$
$\left[H_{2}S{o}_4\right]=\left[NaOH\right]={10}^{-2}$
$H_{2}S{o}_4=2H^{+}+S{o}_4^{2-}$
$\therefore \left[H^{+}\right]=2\times \left[H_{2}S{o}_4\right]=2\times {10}^{-2}$
$\therefore pH=-\log \left[H^{+}\right]=\log 2\times {10}^{-2}$
$=1.7A$