State whether the following statement is true or false:
The decomposition reaction of silver bromide into silver and bromine by light is used in the manufacturing of cement.

Which among the following statement$(s)$ is(are) true? Exposure of silver chloride to sunlight for a long duration turns grey due to:
$(i)$ The formation of silver by decomposition of silver chloride
$(ii)$ Sublimation of silver chloride
$(iii)$ Decomposition of chlorine gas from silver chloride
$(iv)$ Oxidation of silver chloride

What happens when a piece of $Zn$ metal is added to $CuSO_4$ solution?

Identify the type of reactions in each of the following reactions:
$(i)$ $Zn + H_{2}SO_{4} \longrightarrow ZnSO_{4} + H_{2}$
$(ii)$ $CaO + H_{2}O \longrightarrow Ca(OH)_{2}$

Why does the colour of copper sulphate solution change when an iron nail is dipped in it?

When hydrogen gas burns in the presence of oxygen,water is formed,and when water is electrolysed,hydrogen and oxygen gases are produced. State the kind of reaction that takes place:
$(a)$ In the first case
$(b)$ In the second case