Question

A solution has ${10}^{-2}M$ hydrogen ions in it. The solution is diluted by 100 times. The pH of the solution is:

• A. 2
• B. 4
• C. 7
• D. 3

Answer 1

The correct option is B 4

$\left[H^{+}\right]={10}^{-2}M$

Every 10 times dilution increases the pH of an acidic solution by 1.

If it is diluted 100 times, its $\left[H^{+}\right]={10}^{-4}M$

PH = $-log\left[H^{+}\right]$ = $-log\left[{10}^{-4}\right]$

Therefore, its pH = 4