Question

Which one of the following is a polyacidic base ?

• A. $Ca(OH{)}_2$
• B. $Al(OH{)}_3$
• C. (a) and (b) above.
• D. None of the above

Answer 1

The correct option is C (a) and (b) above.

Polyacidic bases has more than one ionizable $O{H}^{-}$
calcium hydroxide $\left(Ca\right(OH{)}_2)$ has two ionizable $O{H}^{-}$ while Aluminium hydroxide $\left(Al\right(OH{)}_3)$ has three ionizable $O{H}^{-}$ hence, both are polyacidic base.