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=overset(OH)overset("|  ")underset(OH)underset("|  ")"P "-OH`
 Orthophosphoric acid, `H_(3)PO_(4)` forms three types of salts.
`H_(2).PO_(2)^(-)` 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.