What happens when a piece of $(i)$ Silver metal is added to copper sulphate solution? Also,write the balanced chemical equation if the reaction occurs.

Which among the following changes are exothermic or endothermic in nature?
$(a)$ Decomposition of ferrous sulphate
$(b)$ Dilution of sulphuric acid
$(c)$ Dissolution of sodium hydroxide in water
$(d)$ Dissolution of ammonium chloride in water

Which one of the following is a chemical change? Give reason also.
$A$. Burning of wax
$B$. Melting of wax

Ferrous sulphate decomposes with the evolution of a gas having a characteristic odour of burning sulphur. Write the chemical reaction involved and identify the type of reaction.

Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.
$(a)$ Ethanol is warmed with ethanoic acid to form ethyl acetate in the presence of concentrated $H_2SO_4$.
$(b)$ Ethene is burnt in the presence of oxygen to form carbon dioxide, water and releases heat and light.

Identify the reducing agent in the following reactions:
$(a)$ $4 NH_{3} + 5 O_{2} \longrightarrow 4 NO + 6 H_{2}O$
$(b)$ $H_{2}O + F_{2} \longrightarrow HF + HOF$
$(c)$ $Fe_{2}O_{3} + 3 CO \longrightarrow 2 Fe + 3 CO_{2}$
$(d)$ $2 H_{2} + O_{2} \longrightarrow 2 H_{2}O$