# How do you write the ionization equation for calcium hydroxide: Ca(OH)2?

## This is a base that would ionize completely, and the dissociation equation would look like this: Ca(OH)2 <----> Ca2+ 2OH- , but how would I write the Bronsted equation with water? Ca(OH)2 + H2O --> ? I know that water auto-ionizes to make H3O+ and OH-.

Nov 21, 2017

$C a {\left(O H\right)}_{2} \left(s\right) \to C {a}^{2} + \left(a q\right) + O {H}^{-} \left(a q\right)$

#### Explanation:

There is no need to include water in the ionization equation, you just need to include the states in your equation:

$C a {\left(O H\right)}_{2} \left(s\right) \to C {a}^{2 +} \left(a q\right) + O {H}^{-} \left(a q\right)$

You may want to write an equation corresponding to the hydroxide displacement in water (The Grotthuss mechanism) but it is not a measurable process since the reactants and products are the same.

$O {H}^{-} + {H}_{2} O \to O {H}_{2} + H {O}^{-}$