What are the oxidation states of phosphorus in the following:
(i)`H_(3)PO_(3)` , (ii)`PCl_(3)` , (iii)`Ca_(3)P_(2)`
(iv)`Na_(3)PO_(4)` , (v)`POF_(3)`

Explanation

(i) Let the oxidation state of P be x.
`{:((i),overset(+1)(H_(3))overset(x)(P)overset(-2)(O_(3))" "therefore" "3(+1)+x+3(-2)=0 or x = +3,(ii),overset(x)(P)overset(-1)(Cl_(3))" "therefore" "x+3(-1)=0 or x = +3),((iii),overset(+2)(Ca_(3))overset(x)(P_(2))" "therefore" "3(+2)+2 xx x = 0 or x = -3,(iv),overset(+1)(Na_(3))overset(x)(P)overset(-2)(O_(4))" "therefore" "3(+1)+x+4(-2)=0 or x = +5),((v),overset(x)(P)overset(-2)(O)overset(-1)(F_(3))" "therefore" "x + 1 (-2)+3(-1)=0 or x = +5,,):}`