# What are hydroxide ions produced by?

May 9, 2017

Amongst other processes, by the $\text{autoprotolysis reaction}$ of water...........

#### Explanation:

And the autoprotolysis of water can be represented by the following reaction:

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

This reaction shares the properties of all stoichiometric reactions.: (i) mass is balanced; and (ii) charge is balanced. This is an equilibrium reaction, and has been carefully measured under specific conditions; at $298 \cdot K$, and $1 \cdot a t m$.......the ion product gives............

$\left[H {O}^{-}\right] \left[{H}_{3} {O}^{+}\right] = {10}^{- 14}$

And this equilibrium defines the $p H$ scale, when we take $- {\log}_{10}$ of each side to give $p H + p O H = 14$.

Under non-standard conditions, say at $373 \cdot K$, given that this is a bond-breaking reaction, how do you think the equilibrium constant will evolve?

May 9, 2017

Hydroxide ions sources are usually alkaline metals

#### Explanation:

Hydroxide ions come from many sources. In synthetic chemistry, the most likely source of hydroxide ions will probably be from alkaline metal hydroxides. These are compounds such as NaOH, KOH. They can also be produced by alkaline earth metal hydroxides like $M g {\left(O H\right)}_{2}$.