Question

2 grams of ferrous sulphate crystals are heated in a boiling tube state the colour of ferrous sulphate crystal before and after heating

Answer 1

Ferrous sulphate crystals contain water molecules (FeSO4. 7H2O). On heating, ferrous sulphate crystals lose water and anhydrous ferrous sulphate (FeSO4) is formed. So their colour changes from light green to white.On further heating, anhydrous ferrous sulphate decomposes to form ferric oxide (Fe2O3), sulphur dioxide (SO2) and sulphur trioxide (SO3). So, the gas emitted smells like burning sulphur. In this reaction, the single reactant FeSO4 decomposes to form three different products. So, the reaction is a decomposition reaction