Question

The pH of solution on mixing equal volume of solution having pH = 3 and pH = 4 is: $[log5.5=0.7404]$

• A. 3.38
• B. 3.5
• C. 3.26
• D. 4

Answer 1

The correct option is C 3.26

$p{H}_1=3$

$\Rightarrow [H^{+}{]}_1={10}^{-3}$

Similarily,

$[H^{+}{]}_2={10}^{-5}$

In the final solution, the concentration of $H^{+}$ ion is given by,

$\left[H^{+}\right]=\frac{{10}^{-5}+{10}^{-3}}{2}$

$\Rightarrow \left[H^{+}\right]=5.5\times {10}^{-4}$

Therefore, pH of the solution is given by,

$pH=-log\left[H^{+}\right]$

$\Rightarrow pH=-log(5.5\times {10}^{-4})$

$\Rightarrow pH=3.26$