Question

$pH$ of a dilute solution of $HCl$ is $6.95$. Calculate molarity of $HCl$ solution.
$\left[\begin{array}{c}{10}^{-6.95}=11.22\times {10}^{-8}\\ {10}^{-7.05}=8.90\times {10}^{-8}\end{array}\right]$

Answer 1

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

so, $\left[H^{+}\right]={10}^{-pH}$

Here, pH = 6.95

So, concentration $\left[H^{+}\right]=10-6.95=1.12\times {10}^{-7}M$

So, molarity of HCl solution is $1.12\times {10}^{-7}.$