Given are H ₃ PO ₂, H ₃ PO ₃, H ₃ PO ₄ and H ₄ P ₂ O ₇ . Which of the above oxacids results into two series of salts?

Step-by-step solution

The number of series of salts formed by an oxoacid is equal to its basicity, which corresponds to the number of ionizable hydrogen atoms attached to oxygen atoms (P-OH groups). For H ₃ PO ₂ (hypophosphorous acid), the structure is H ₂ P(O)OH . It has only one P-OH group, so it is monobasic and forms one series of salts. For H ₃ PO ₃ (phosphorous acid), the structure is HP(O)(OH) ₂ . It has two P-OH groups, so it is dibasic and forms two series of salts (acid salts and normal salts). For H ₃ PO ₄ (phosphoric acid),