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

Given,

pH = 3.76

It is known that,

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

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

$\Rightarrow\left[\mathrm{H}^{+}\right]=\operatorname{antilog}(-\mathrm{pH})$

$=\operatorname{antilog}(-3.76)$

$=1.74 \times 10^{-4} \mathrm{M}$

Hence, the concentration of hydrogen ion in the given sample of vinegar is $1.74 \times 10^{-4} \mathrm{M}$.