Question

200 ml of solution with $pH=6$ is mixed with 200 ml of solution with $pH=8$. The final $pH$ of the solution is:

• A. 7
• B. 6
• C. 12
• D. 14

Answer 1

The correct option is A 7

$p{H}_1=6\Rightarrow \left[H^{+}\right]={10}^{-6}$

$p{H}_2=8\Rightarrow pO{H}_2=6$

$\Rightarrow [O{H}^{-}{]}_2={10}^{-6}$

$\therefore \left[H^{+}\right]$ and $\left[O{H}^{-}\right]$

neutralize when mixed

$\therefore p{H}_{res}=7$