In a school laboratory, a student wants to study the effect of heat on the ferrous sulphate crystals in a boiling tube. State the conclusion he is likely to draw on the basis of his observations

Following observations can be drawn:
(i) The colour of ferrous sulphate on gentle heating first changes to white then on strong heating, it changes to brown.
(ii) A gas having a smell of burning sulphur is evolved.
(iii) Brown coloured gas is evolved.