List I (Oxoacids of phosphorous)		List II (Characteristic bonds)
I)	Phosphinic acid	P)	Contains P – O – P linkage
II)	Phosphonic acid	Q)	Contains P = O linkage
III)	Hypophosphoric acid	R)	Contains P – OH linkage
IV)	Pyrophosphoric acid	S)	Contains P – H linkage
		T)	Contains P – P linkage

Correct match is:

Phosphinic acid(Hypophosphorous acid): $H_{3}P{O}_2$  : contains one P – OH, two P – H and  one P=O
Phosphonic acid (orthphosphorous acid): $H_{3}P{O}_3$ : contains  two P – OH, one P – H and  one P=O bonds
Hypophosphoric acid :  $H_4{P}_2{O}_6$: contains four P – OH, one P – P and two P=O bonds
Pyrophosphoric acid:  $H_4{P}_2{O}_7$ : contains four P – OH, one P – O – P  and two P=O bonds