Q38 / 180 · COMEDK 2020 · Chemistry
Hydroxyl ion concentration of $1 \mathrm{M} \mathrm{HCl}$ is
- Correct answerA$1 \times 10^{-14} \mathrm{~mol} \mathrm{dm}^{-3} \quad$
- B$1 \times 10^{-1} \mathrm{~mol} \mathrm{dm}^{-3}$
- C$1 \times 10^{-13} \mathrm{~mol} \mathrm{dm}^{-3} \quad$
- D$1 \times 10^{1} \mathrm{~mol} \mathrm{dm}^{-3}$
Solution
For $1 \mathrm{M} \mathrm{HCl}$,
$$
\begin{aligned}
{\left[\mathrm{H}^{+}\right]=1 } &=10^{0} \\
{\left[\mathrm{H}^{+}\right]\left[\mathrm{OH}^{-}\right] } &=10^{-14} \\
{\left[\mathrm{OH}^{-}\right] } &=10^{-14} \mathrm{~mol} \mathrm{dm}{ }^{-3} .
\end{aligned}
$$
Hence, the correct answer is option: 'A'.