Chapter 21, Problem 1TS

Show that the pH of a solution is $10$ when the hydronium ion concentration of this solution is $1\times {10}^{-10}\text{ M}$ . Is the solution acidic or basic?

To determine

The value of pH as $10$ and to conclude if it is acidic or basic.

Answer to Problem 1TS

The pH is $10$ and so the solution is basic.

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 $1\times {10}^{-10}\text{ M}$ .

So, the pH can be calculated as,

$\begin{array}{c}\text{pH}=-\log {\text{[H}}^{+}]\\ =-\log (1\times {10}^{-10}\text{ M})\\ =-(-10)\\ =10\end{array}$

So, the pH is $10$ .

The pH scale is from $0-14$ . The pH after $\text{7}$ is for basic substances. So, the solution is basic.

Conclusion:

Therefore, the pH is $10$ and so the solution is basic.