Question

The oxidation states of P in the following compounds

H₃PO_3, PCl_3, Ca₃P_2, Na₃PO_4, ​POF₃ are respectively be

• A. + 3, + 3, - 3, + 5, + 5
• B. + 5, + 5, - 3, + 3, + 3
• C. + 4, + 3, - 3, + 4, + 5
• D. + 3, + 3, - 2, + 4, + 5

Answer 1

Answer: (A)

Let the oxidation state of phosphorus be x.

(i) H₃PO₃ (3 $\times$ + 1) + x + (3 $\times$ - 2) = 0

x = + 3

(ii) PCl₃ x + (3 $\times$ - 1)

x = + 3

(iii) Ca₃P₂ (3 $\times$ + 2) + 2x

x = - 3

(iv) Na₃PO₄ (3 $\times$ 1) + x + (4 $\times$ - 2)

x = + 5

(v) POF₃ x + (- 2) + (3 $\times$ - 1)

x = + 5