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

On adding a drop of barium chloride solution to an aqueous solution of sodium sulphite,a white precipitate is obtained.
$(a)$ Write a balanced chemical equation of the reaction involved.
$(b)$ What other name can be given to this precipitation reaction?
$(c)$ On adding dilute hydrochloric acid to the reaction mixture,the white precipitate disappears. Why?

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.

Write the chemical equation of the reaction with an example in which a change in colour takes place.

What type of coating is formed on silver articles when they get corroded?

What happens when zinc granules are treated with dilute solutions of $H_{2}SO_{4}$,$HCl$,and $HNO_{3}$? Also,write the chemical equations if a reaction occurs.