Question

If pH value of a solution is $3$ and by adding water, it becomes $6$, then the dilution is increased by

• A. 500 times
• B. 10 times
• C. 1000 times
• D. 100 times.

Answer 1

Answer: (C)

Given: Initial $pH =3$ and final $pH =6 . We$ know that $pH \propto$ Dilution.

Therefore initially $\left[ H ^{+}\right]=$ $10^{-3}$ and after dilution $\left[ H ^{+}\right]=10^{-6} $ Thus increase in dilution

$=\frac{\text { Original } H ^{+} \text {concentration }}{\text { Concentration of } H +\text { after dilution }}=\frac{10^{-3}}{10^{-6}}=10^{3} $

$=1000$ times