The following reaction is an example of a:
$4 NH_{3}(g) + 5 O_{2}(g) \longrightarrow 4 NO(g) + 6 H_{2}O(g)$
$(i)$ displacement reaction
$(ii)$ combination reaction
$(iii)$ redox reaction
$(iv)$ neutralisation reaction

What happens when hydrogen gas is passed over heated copper oxide $(CuO)$?

Give reason why:
$(i)$ Sodium acts as a reducing agent while chlorine acts as an oxidising agent in the following reaction:
$2 Na (s) + Cl_2 (g) \rightarrow 2 NaCl (s)$

Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.
$(a)$ Ethanol is warmed with ethanoic acid to form ethyl acetate in the presence of concentrated $H_2SO_4$.
$(b)$ Ethene is burnt in the presence of oxygen to form carbon dioxide, water and releases heat and light.

Give the characteristic tests for the following gases:
$(a)$ $O_2$
$(b)$ $H_2$

Which of the following are combination reactions?
$(i) 2 KClO_3 \xrightarrow{\text{Heat}} 2 KCl + 3 O_2$
$(ii) MgO + H_2O \longrightarrow Mg(OH)_2$
$(iii) 4 Al + 3 O_2 \longrightarrow 2 Al_2O_3$
$(iv) Zn + FeSO_4 \longrightarrow ZnSO_4 + Fe$