Question

The pH of a sample of vinegar is $3.76$. Calculate the concentration of hydrogen ions in it.

Answer 1

Step 1. Formula for pH

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

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

Step 2. Calculation of hydrogen ions

$$\begin{gathered} \text{3.76}=-\log \left[{\text{H}}^{+}\right] \\ \left[{\text{H}}^{+}\right]={10}^{-3.76} \\ =0.000173 \\ =1.73\times {10}^{-4}\text{M} \end{gathered}$$

Hence, the concentration of hydrogen ions is $1.73\times {10}^{-4}\text{M}$.