Explain the "Oxidation" in terms of gain or loss of oxygen with two examples.

In the refining of silver,the recovery of silver from silver nitrate solution involves displacement by copper metal. Write down the reaction involved.

Which of the statements about the reaction below are incorrect?
$2 PbO_{(s)} + C_{(s)} \longrightarrow 2 Pb_{(s)} + CO_{2(g)}$
$(a)$ Lead is getting reduced.
$(b)$ Carbon dioxide is getting oxidised.
$(c)$ Carbon is getting oxidised.
$(d)$ Lead oxide is getting reduced.

$Fe_{2}O_{3} + 2Al \rightarrow Al_{2}O_{3} + 2Fe$
The above reaction is an example of a:

Why do we apply paint on iron articles?

Write the balanced chemical equations for the following reactions.
$(a)$ Calcium hydroxide $+$ Carbon dioxide $\rightarrow$ Calcium carbonate $+$ Water
$(b)$ Zinc $+$ Silver nitrate $\rightarrow$ Zinc nitrate $+$ Silver
$(c)$ Aluminium $+$ Copper chloride $\rightarrow$ Aluminium chloride $+$ Copper
$(d)$ Barium chloride $+$ Potassium sulphate $\rightarrow$ Barium sulphate $+$ Potassium chloride