Question

Complete and balance the following equations:
(i) Al + O₂ $\stackrel{}{\to }$
(ii) Al + N₂ $\stackrel{}{\to }$
(iii) Al + KOH + H₂O $\stackrel{}{\to }$
(iv) Fe₂O₃ + ______ $\stackrel{}{\to }$ Al₂O₃ + _______.
(v) Fe₂O₃ + CO $\stackrel{}{\to }$

Answer 1

The complete and balanced equations are given below:

(i) Aluminium burns in air, forming aluminium oxide.

$$\begin{gathered} 4\mathrm{Al}+3{\mathrm{O}}_2\stackrel{}{\to }2{\mathrm{Al}}_2{\mathrm{O}}_3 \\ \mathrm{Aluminium}\mathrm{air}\mathrm{Aluminium}\mathrm{oxide} \end{gathered}$$

(ii) When heated to very high temperatures, aluminium burns brightly in air and reacts with nitrogen to form aluminium nitride.

$$\begin{gathered} 2\mathrm{Al}+{\mathrm{N}}_2\stackrel{}{\to }2\mathrm{AlN} \\ \mathrm{Aluminium}\mathrm{Nitrogen}\mathrm{Aluminium}\mathrm{nitride} \end{gathered}$$

(iii) Aluminium reacts with potassium hydroxide to form potassium aluminate, liberating hydrogen gas in the process.

$$\begin{gathered} 2\mathrm{Al}+2\mathrm{KOH}+2{\mathrm{H}}_2\mathrm{O}\stackrel{}{\to }2{\mathrm{KAlO}}_2+3{\mathrm{H}}_2 \\ \mathrm{Aluminium}\mathrm{Potassium}\mathrm{Potassium}\mathrm{Hydrogen}\mathrm{gas} \\ \mathrm{hydroxide}\mathrm{aluminate} \end{gathered}$$

(iv) Aluminium acts as a reducing agent at high temperatures. Aluminium reduces ferric oxide to iron, forming aluminium oxide.
$$\begin{gathered} {\mathrm{Fe}}_2{\mathrm{O}}_3+2\mathrm{Al}\stackrel{}{\to }{\mathrm{Al}}_2{\mathrm{O}}_3+2\mathrm{Fe} \\ \mathrm{Ferric}\mathrm{oxide}\mathrm{Aluminium}\mathrm{Aluminium}\mathrm{oxide}\mathrm{Iron} \end{gathered}$$

(v) Ferric oxide undergoes reduction with carbon monoxide to form iron and carbon dioxide.

$$\begin{gathered} {\mathrm{Fe}}_2{\mathrm{O}}_3+3\mathrm{CO}\stackrel{\mathrm{heat}}{\to }2\mathrm{Fe}+3{\mathrm{CO}}_2 \\ \mathrm{Ferric}\mathrm{oxide}\mathrm{Carbon}\mathrm{Iron}\mathrm{Carbon}\mathrm{dioxide} \\ \mathrm{monoxide} \end{gathered}$$