Ncert Exercises & Solutions

What are the oxidation states of phosphorus in the following:
(i) H₃PO₃ (ii) PCl₃ (iii) Ca₃P₂ (iv) Na₃PO₄ (v) POF₃?

Let the oxidation state of P be x.

(i)H₃PO₃

3+x+3(-2) = 3+x-6=0 x-3= 0 x=+3

(ii) PCl₃

x+3(-1)= 0 x-3=0 x=+3

(iii) Ca₃P₂

3(+2)+2(x)=0 6+2x=0 2x=-6 x=-3

(iv) Na₃PO₄

3(+1)+x+4(-2)=0 3+x-8=0 x-5=0 x=+5

(v) POF₃

x+(-2)+3(-1)=0 x-5=0 x=+5