A 0.0729*g mass of HCl(g) was dissolved in a 50*mL volume of water. What is pH of this solution?

Oct 27, 2016

pH=-log_10[H_3O^+]=??

$p H < 3$

Explanation:

$H C l \left(g\right) + {H}_{2} O \left(l\right) \rightarrow {H}_{3} {O}^{+} + C {l}^{-}$

This reaction is essentially quantitative, and the solution will be stoichiometric in ${H}_{3} {O}^{+}$.

$\text{Moles of HCl}$ $=$ $\frac{0.0729 \cdot g}{36.46 \cdot g \cdot m o {l}^{-} 1}$

And thus $\left[{H}_{3} {O}^{+}\right] = \frac{0.0729 \cdot g}{36.46 \cdot g \cdot m o {l}^{-} 1} \times \frac{1}{50 \times {10}^{-} 3 L}$; this gives an answer in $m o l \cdot {L}^{-} 1$ as is required for a concentration.

And finally.....................

$p H = - {\log}_{10} \left\{\frac{0.0729 \cdot g}{36.46 \cdot g \cdot m o {l}^{-} 1} \times \frac{1}{50 \times {10}^{-} 3 L}\right\}$

$=$ ??

What is $p O H$ of this solution?