# Question ef8de

Aug 10, 2017

At pH 7 the amount of acid ions is exactly equal to the amount of basic ions.

#### Explanation:

At pH 7 the ${H}^{+}$ concentration is ${10}^{-} 7$

pH is the negative log of the hydrogen ion concentration so

the antilog of  10^-7 is 7

Kw for water is ${10}^{-} 14.$

${10}^{-} 14 = \frac{{H}^{+} \times O {H}^{-}}{{H}^{2} O}$

The concentration of water ${H}_{2} O$ is one. so

${10}^{-} 14 = {H}^{+} \times O {H}^{-}$

if ${H}^{+} = {10}^{-} 7$ Then

${10}^{-} 14 = {10}^{-} 7 \times O {H}^{-} 1$ Dividing both sides by ${10}^{-} 7$

$\frac{{10}^{-} 14}{{10}^{-} 7} =$OH# so

${10}^{-} 7 = O {H}^{-} 1$

So when the ${H}^{+}$ concentration is ${10}^{-} 7$ The $O {H}^{-} 1$ concentration is also ${10}^{-} 7$

At pH 7 the concentration of acid and base are equal