Which of the following are exothermic processes?
$(i)$ Reaction of water with quicklime
$(ii)$ Dilution of an acid
$(iii)$ Evaporation of water
$(iv)$ Sublimation of camphor (crystals)

$2 \, g$ of ferrous sulphate crystals are heated in a boiling tube.
$(i)$ State the colour of ferrous sulphate crystals both before heating and after heating.
$(ii)$ Name the gases produced during heating.
$(iii)$ Write the chemical equation for the reaction.

What happens when a piece of
$(a)$ zinc metal is added to copper sulphate solution?
$(b)$ aluminium metal is added to dilute hydrochloric acid?
$(c)$ silver metal is added to copper sulphate solution?
Also,write the balanced chemical equation if the reaction occurs.

Which of the following is not a physical change?

Write a balanced chemical equation for each of the following reactions and also classify them.
$(a)$ Iron $(III)$ oxide on heating with carbon monoxide gas reacts to form solid iron and liberates carbon dioxide gas.
$(b)$ Hydrogen sulphide gas reacts with oxygen gas to form solid sulphur and liquid water.

Identify the type of reactions in each of the following reactions:
$(i)$ $CaCO_{3} \xrightarrow{\text{Heat}} CaO + CO_{2}$
$(ii)$ $AgNO_{3}(aq) + NaCl(aq) \longrightarrow AgCl(s) \downarrow + NaNO_{3}(aq)$