Question

The hydrogen ion concentration of a solution is $3.98\times {10}^{-6}$ mole per litre. The $pH$ value of this solution will be:

• A. $6.0$
• B. $5.8$
• C. $5.4$
• D. $5.9$

Answer 1

Answer: (C)

$5.4$

$pH$ is the negative log of hydrogen ($H^{+}$) concentration.

Given that, $\left[H^{+}\right]=3.98\times {10}^{-6}$mole per litre

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

$=-\log (3.98\times {10}^{-6})$

$=-\log 3.98-\log {10}^{-6}$

$=-0.59+6=5.40$

Hence, option $C$ is correct.