Chapter 21, Problem 4TS

Show that the pH of a solution is $-0.301$ when its hydronium ion concentration equals $\text{2}$ moles per liter. Is the solution acidic or basic?

To determine

The pH value as $-0.301$ when its hydronium ion concentration is equal to two moles per literand to conclude whether it is acidic or basic.

Answer to Problem 4TS

The pH of the solution is $-0.301$ and the solution is very acidic.

Explanation of Solution

The pH is used for indicating the acidity of the solution. The concentration of hydronium ions is used for calculating the pH. The pH is calculated by taking the negative log of the concentration of the hydronium ions.

The concentration of the hydronium ions is given as two moles per liter.

The pH can be calculated as,

$\begin{array}{c}\text{pH}=-\log {\text{[H}}^{+}]\\ =-\log (2\text{ M})\\ =-(0.301)\\ =-0.301\end{array}$

So, the pH is $-0.301$ .

The pH scales ranges from $0-14$ . The pH before $\text{7}$ is for acidic substances. So, the solution is very acidic.

Conclusion:

Therefore, the pH of the solution is $-0.301$ and the solution is very acidic.