Question

Oxidation numbers of P in PO³⁻₄, of S in SO²⁻₄, and that of Cr in Cr₂ O²⁻₇
are respectively
(a) + 3, + 6 and + 5 (b) + 5, + 3 and + 6
(c) – 3, + 6 and + 6 (d) + 5, + 6 and + 6

Answer 1

(d) + 5, + 6 and + 6

Explanation:

Oxidation numbers are as follows:

P in PO³⁻₄ : -2*4 +x = -3; x = +5

S in SO²⁻₄ : -2*4 +x = -2; x = +6

Cr in Cr₂ O²⁻₇ : -2*7 + 2x = -2; x = +6

We find that the oxidation number of P, S and Cr is 5, 6 and 6 respectively.

Option D is the answer.