Explain the type of reactions represented by the following equations:
$(i)$ $CaO + CO_2 \longrightarrow CaCO_3$
$(ii)$ $2Na + 2H_2O \longrightarrow 2NaOH + H_2$

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.

When potassium iodide solution is added to a solution of lead $(II)$ nitrate in a test tube,a precipitate is formed.
$(i)$ Write a balanced chemical equation for this reaction.
$(ii)$ What type of reaction is this?

You are provided with two containers made of copper and aluminium. You are also provided with solutions of dilute $HCl$,dilute $HNO_{3}$,$ZnCl_{2}$,and $H_{2}O$. In which of the above containers can these solutions be kept?

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)

Three beakers labelled as $A$,$B$ and $C$ each containing $25 \, mL$ of water were taken. $A$ small amount of $NaOH$,anhydrous $CuSO_4$ and $NaCl$ were added to the beakers $A$,$B$ and $C$ respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers $A$ and $B$,whereas in case of beaker $C$,the temperature of the solution falls. Which one of the following statement$(s)$ is(are) correct?
$(i)$ In beakers $A$ and $B$,exothermic process has occurred.
$(ii)$ In beakers $A$ and $B$,endothermic process has occurred.
$(iii)$ In beaker $C$ exothermic process has occurred.
$(iv)$ In beaker $C$ endothermic process has occurred.