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 in `H_3PO_3` is x.
`(+1)xx3+x+(-2)xx3=0impliesx=+3`
(ii). Let the oxidation state of P in `PCl_3` is x.
`x+(-1)xx3=0impliesx=+3`
(iii). Let the oxidation state of P in `Ca_3P_2` is x.
`(+2)xx3+2x=0impliesx=+3`
(iv). Let the oxidation state of P in `Na_2PO_4` is x.
`(+1)xx3+x+(-2)xx4=0impliesx=+5`
(v). Let the oxidation state of P in `POF_3` is x.
`x+(-2)xx1+(-1)xx3=0impliesx=+5`