BIOLOGY AT EASE

 

 AIM : To perform and observe the action of heat on ferrous sulfate crystals and classify the reaction. Materials Needed Ferrous sulfate crystals (FeSO₄·7H₂O), Bunsen burner, Test tube, Test tube holder, Safety goggles, Heat-resistant mat or stand. THEORY Ferrous sulfate (FeSO₄·7H₂O) is a blue-green crystalline compound. When heated, it undergoes dehydration and decomposition. The action of Heat on Ferrous Sulfate Dehydration: Reaction:   ​ FeSO 4 .7H 2 O(s)   →(heat)   FeSO 4 (s) + 7H 2 O Observation: The green crystals lose water and turn white. Type of Change: Physical change (loss of water). Decomposition: Reaction: 2FeSO 4 (s)      →(heat)           Fe 2 O 3 (s)      +  SO 2 (g) + SO 3 (g) ​ Observation: The white powder turns brown, releasing sulfur dioxide (SO₂) and sulfur trioxide (SO₃) gases. Type of Change: Chemical change (formation of new substances). PROCEDURE Step 1: About 5 g ferrous sulphate crystals in a dry boiling tube is taken. Step 2: The colour of the ferrous