Green crystals of $FeSO X_{4} \cdot 7 H X_{2} O$ are heated strongly in a dry tube until no further change occurs. The gaseous products of the final decomposition of the anhydrous $FeSO X_{4}$ (ignoring water vapour) are:

Answer: D

Anhydrous ferrous sulphate decomposes as

2 FeSO X_{4} Fe X_{2} O X_{3} + SO X_{2} + SO X_{3}

. Iron is oxidised from +2 to +3 and sulphur is reduced from +6 to +4 in

SO X_{2}

. Hence both

SO X_{2}

and

SO X_{3}

are evolved and

Fe X_{2} O X_{3}

is left.