Which of the following acids forms three series of salts?

Options

A. `H_(3)PO_(2)`
B. `H_(3)BO_(3)`
C. `H_(3)PO_(4)`
D. `H_(3)PO_(3)`

Answer

C

Explanation

Structure of `H_(3) PO_(4)` is

`H_(3)PO_(4)` has 3 -OH groups , i.e. has three ionisable H-atoms and hence forms three series of salts . These three possible series of salts for `H_(3)PO_(4)` are as follows
`NaH_(2)PO_(4) , Na_(2)HPO_(4)` and `Na_(3)PO_(4)`.