The hydrogen ion concentration of a $10^{-8}$ $\mathrm{M} \mathrm{HCl}$ aqueous solution at $298…
The hydrogen ion concentration of a $10^{-8}$ $\mathrm{M} \mathrm{HCl}$ aqueous solution at $298 \mathrm{~K}\left(\mathrm{~K}_w=\right.$ $\left.10^{-14}\right)$ is:
$1.0 \times 10^{-8} \mathrm{M}$
$1.0 \times 10^{-6} \mathrm{M}$
$1.0525 \times 10^{-7} \mathrm{M}$
$9.525 \times 10^{-8} \mathrm{M}$
Solution
$\left[\mathrm{H}^{+}\right]=10^{-8} \mathrm{M}$
Due to dilute solution.
$\begin{aligned}
{\left[\mathrm{H}^{+}\right] } & =10^{-8}+10^{-7} \mathrm{M} \\
& =10^{-7}[0.1+1] \mathrm{M} \\
& =1.1 \times 10^{-7} \mathrm{M} \\
& =1.1 \times 10^{-7} \mathrm{M}
\end{aligned}$
Caution
In an aqueous solution of $10^{-8} \mathrm{M} \mathrm{HCl},\left[\mathrm{H}^{+}\right]$ is based on the concentration of $\mathrm{H}^{+}$ions of $10^{-8} \mathrm{M} \mathrm{HCl}$ and the concentration of $\mathrm{H}^{+}$ions of water.