Heating ferrous sulphate crystals: type of reaction and equation

The same question, asked 3 times: 2024*, 2025*, 2026. Every wording below, oldest first.

Try each one first, then open its answer.

Question 1
2024
21 (a) $Define a decomposition reaction. Write an equation to show thermal decomposition of ferrous sulphate crystals.$
Question 2
2025
21 (b) $What is observed when hydrated ferrous sulphate crystals are heated in a dry boiling tube ? Give balanced chemical equation(s) of the reactions(s) that occur(s).$
Question 3
2026
26 $2 g of green coloured crystals of ferrous sulphate are heated in a dry boiling tube. Name the type of chemical reaction taking place. Write the balanced chemical equation for the reaction. Is this an exothermic or an endothermic reaction ?$

Question 1