Question

An acid solution of $pH=6$ is diluted ${10}^2$ times. The $pH$ of solution becomes approximately

• A. 6.96
• B. 6
• C. 4
• D. 9

Answer 1

The correct option is A 6.96

$H^{+}$ due to water will come into picture by common ion effect.

$pH=6$ means concentrated of ${10}^{-6}M$

now after dilution of ${10}^{-2}:$ concentration is ${10}^{-8}M$

Since it's weaker than $H^{+}$ concentration of water hence $H^{+}$ from water will come into picture so now concentration will be:

${10}^{-7}+{10}^{-8}=1.1\times {10}^{-7}$

Hence $pH$ is negative log of $H^{+}$ concentration i.e. $6.958$.

Hence, the correct option is $\text{A}$