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

What happens when dilute hydrochloric acid is added to iron filings? Tick the correct answer.

Translate the following statements into chemical equations and then balance them.
$(a)$ Hydrogen gas combines with nitrogen to form ammonia.
$(b)$ Hydrogen sulphide gas burns in air to give water and sulphur dioxide.
$(c)$ Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate.
$(d)$ Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.

Write the balanced chemical equation for the following and identify the type of reaction in each case.
$(a)$ Potassium bromide $(aq) +$ Barium iodide $(aq) \rightarrow$ Potassium iodide $(aq) +$ Barium bromide $(s)$
$(b)$ Zinc carbonate $(s) \rightarrow$ Zinc oxide $(s) +$ Carbon dioxide $(g)$
$(c)$ Hydrogen $(g) +$ Chlorine $(g) \rightarrow$ Hydrogen chloride $(g)$
$(d)$ Magnesium $(s) +$ Hydrochloric acid $(aq) \rightarrow$ Magnesium chloride $(aq) +$ Hydrogen $(g)$

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.

Why do we apply paint on iron articles?