Complete the following reaction:
$2 FeSO_{4} \xrightarrow{\text{Heat}} Fe_{2}O_{3} + \dots + \dots$

$A, B$ and $C$ are three elements which undergo chemical reactions according to the following equations:
$A_{2}O_{3} + 2B \rightarrow B_{2}O_{3} + 2A$
$3CSO_{4} + 2B \rightarrow B_{2}(SO_{4})_{3} + 3C$
$3CO + 2A \rightarrow A_{2}O_{3} + 3C$
Answer the following questions with reasons:
$(a)$ Which element is the most reactive?
$(b)$ Which element is the least reactive?
$(c)$ What is the type of reactions listed above?

Write balanced chemical equations for the following reactions:
$(i)$ Calcium carbonate on reaction with hydrochloric acid gives calcium chloride,water and carbon dioxide.
$(ii)$ Nitrogen reacts with hydrogen under pressure to form ammonia.
$(iii)$ Carbon disulphide burns in air to give carbon dioxide and sulphur dioxide.

Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.
$(a)$ Thermit reaction,iron $(III)$ oxide reacts with aluminium and gives molten iron and aluminium oxide.
$(b)$ Magnesium ribbon is burnt in an atmosphere of nitrogen gas to form solid magnesium nitride.

Why is a combustion reaction considered an oxidation reaction?

Write the balanced chemical equations for the following reactions:
$(a)$ Sodium carbonate on reaction with hydrochloric acid in equal molar concentrations gives sodium chloride and sodium hydrogencarbonate.
$(b)$ Sodium hydrogencarbonate on reaction with hydrochloric acid gives sodium chloride,water,and liberates carbon dioxide.
$(c)$ Copper sulphate on treatment with potassium iodide precipitates cuprous iodide $(Cu_2I_2)$,liberates iodine gas,and also forms potassium sulphate.