What is the basicity of orthophosphoric acid ? Write the types of salts formed by it. 

Explanation

Orthophosphoric acid, `H_(3)PO_(4)` has three -OH groups and its basicity is 3
`O=underset(OH)underset(|)overset(OH)overset(|)P-OH`
Orthophosphoric acid, `H_(3)PO_(4)` forms three types of salts.
`H_(2)PO_(4)^(-)` is the anion of primary salt, an acidic salt. `HPO_(4)^(2-)` is the anion of secondary salt, an acidic salt. `PO_(4)^(3-)` is the anion of tertiary salt, normal salt.