Chapter EH, Problem 6R

Solution

Interpretation: Whether the given solution is an acid or a base need to be determined. The pH of the solution needs to be calculated.

Concept Introduction: A substance is said to be acidic if it gives hydrogen ions in an aqueous solution. Thus, a solution is acidic in nature if there are a greater number of hydrogen ions as compared to hydroxide ions. The pH of a solution can be calculated as follows:

  $\text{pH}=-\log \left(\left[{\text{H}}^{+}\right]\right)$

Here, $\left[{\text{H}}^{+}\right]$ is the hydrogen ion concentration.

For any solution, if pH is less than 7, it is considered acidic in nature and if pH is more than 7, it is considered basic in nature.

Acidic and 3.495

The hydrogen ion concentration of the solution is $3.2\times {10}^{-4}\text{ mol/L}$ . The pH of the solution is calculated as follows:

  $\text{pH}=-\log \left(\left[{\text{H}}^{+}\right]\right)$

Substituting the value,

  $\begin{array}{c}\text{pH}=-\log \left(3.2\times {10}^{-4}\text{ mol/L}\right)\\ =-\log \left(3.2\right)-\log \left({10}^{-4}\right)\\ =-0.5051+4\\ =3.495\end{array}$

Thus, the pH of the solution is $3.495$ .

Since the pH of the solution is less than 7, thus, the solution is acidic in nature.

Thus, the given solution is acidic and the pH of the solution is 3.495.