Identify di acidic base from the following 

Mono acidic base: A base which produce one hydroxyl ion by the ionization of one molecule of a base, is called a mono acidic base.

Di acidic base: A base which produce two hydroxyl ions by the ionization of one molecule of the base is called di acidic base.

$\text{ Ex: }\mathrm{Ca}(\mathrm{OH}{)}_2,\mathrm{Mg}(\mathrm{OH}{)}_2,\mathrm{Cu}(\mathrm{OH}{)}_2,\mathrm{Mn}(\mathrm{OH}{)}_2,\mathrm{Fe}(\mathrm{OH}{)}_2,\mathrm{Ba}(\mathrm{OH}{)}_2\text{ etc. }$

Tri acidic base: A base which produces three hydroxyl ions by the ionization of one molecule of the base is called a triacidic base.

$\mathrm{Ex}:\mathrm{Fe}(\mathrm{OH}{)}_3,\mathrm{Al}(\mathrm{OH}{)}_3,\mathrm{Cr}(\mathrm{OH}{)}_3$