In which substance does phosphorus have a + 3 oxidation state

Options are as follow,

A. P₄O₁₀

B. PCl₅

C. Ca₃ (PO₄) ₂

D. KH ₂PO₃

Answer;

The correct option is Option-D (KH₂PO₃).

Explanation:

Oxidation number of Phosphorous is calculated as,

As the normal oxidation number of K is + 1, H is + 1 and O is - 2 so,

KH₂PO₃ = 0

0 shows that the molecule is neutral. Now puttion values of all elemnts except P,

(+1) + (+1) ₂ + P + (-2) ₃ = 0

+1 + 2 + P - 6 = 0

+3 + P - 6 = 0

+3 + P = + 6

P = + 6 - 3

P = + 3