Question

Oxidation states of P in H₄P₂O₅, H₄P₂O₆, and H₄P₂O₇, are respectively:
(a) + 3, + 5, + 4
(b) + 5, + 3, + 4
(c) + 5, + 4, + 3
(d) + 3, + 4, + 5

Answer 1

Oxidation state of H is +1.

Oxidation state of O is - 2

Let oxidation state of P be x in each case

In H4P205,

4(+1) + 2x + 5(-2) = 0

4 - 10+ 2x = 0

2x = 6

x = +3.

InH4P2O6

4(+1) + 2x +6(-2) = 0

4 - 12 +2x = 0

2x = 8

x = +4.

In H4P2O7

4(+1) + 2x + 7(-2) = 0

4 - 14 +2x = 0

2x = 10

x = +5.