Oxidation numbers of P in , of S in and that of Cr in are respectively,
(a) +5, +6 and +6 (b) +3, +6 and +5
(c) +5, +3 and +6 (d) -3, +6 and +6
Key Idea (i) Sum of oxidation states of all atoms = charge of ion.
(ii) Oxidation number of oxygen = -2
Let the oxidation state of P in be x.