Question

Arrange the following in the increasing order of property mentioned :

H₃PO₃, H₃PO₄, H₃PO₂ (Reducing character)

 

Answer 1

(a) Reducing character: H₃PO₄ < H₃PO₃ < H₃PO₂

This trend can be explained on the basis of structures of oxyacids of phosphorus.

The higher the number of P−H bond, the higher the reducing power of the oxyacid of phosphorus. There are two P−H bonds in H₃PO₂, one P−H bond in H₃PO₃ and no P−H bond in H₃PO₄. So, this explains the reducing trend of the given oxyacids of phosphorus.