# What is meant by the self-ionization of water?

Jan 15, 2018

It refers to the autoprotolysis reaction....

#### Explanation:

$2 {H}_{2} O \left(l\right) r i g h t \le f t h a r p \infty n s {H}_{3} {O}^{+} + H {O}^{-}$

Water undergoes a measurable self-ionization....and under standard conditions, we write....

${K}_{\text{autoprotolysis of water}} = {10}^{-} 14 = \left[{H}_{3} {O}^{+}\right] \left[H {O}^{-}\right]$

And we can further use this expression by taking ${\log}_{10}$ of both sides.....

$p {K}_{a} = 14 = p H + p O H$...where $p H = - {\log}_{10} \left[{H}_{3} {O}^{+}\right]$, and $p O H = - {\log}_{10} \left[H {O}^{-}\right]$

Under non-standard conditions, i.e. $T = 373 \cdot K$, how would you expect the equilibrium to evolve? Would it shift left or right?