Question

Give reasons for the following : H₃PO₂ is a stronger reducing agent than H₃PO₃.

 

Answer 1

Greater the number of element−hydrogen (E−H) bonds present in a compound, greater is the reducing nature of the compound. H₃PO₂has two P−H bonds while H₃PO₃ has one P−H bond. Thus, H₃PO₂ is a stronger reducing agent than H₃PO₃.

Answer 2

In case of H₃PO₃, there is only one P-H bond while in case of H₃PO₂, there are two P-H bonds. Hence H₃PO₂ is better reducing agent than H₃PO_3.