# What is the acid concentration of a sample of acid rain with a pH of 4.20?

Nov 13, 2016

$6.3 \times {10}^{-} 5$mol/L

#### Explanation:

$p H = - {\log}_{10} \left[{H}^{+}\right]$

Given that $p H$ is 4.2

$\therefore 4.2 = - {\log}_{10} \left[H +\right]$

${10}^{- 4.2} = \left[{H}^{+}\right]$

Taking antilog we get

$\left[{H}^{+}\right] = 6.3 \times {10}^{- 5}$ mol/L