Question

Write balanced chemical equations for the following:
(a) burning of coal (carbon) in a sufficient supply of air
(b) When coal burns in insufficient amount of oxygen, carbon monoxide is formed.
(c) Name the type of reaction in each of the above cases.
(d) How is carbon monoxide harmful?

Answer 1

(a) Coal (carbon) burns with adequate amount of oxygen in the air to form carbon dioxide. The balanced chemical equation for this reaction is given below:
$$\begin{gathered} \mathrm{C}+{\mathrm{O}}_2\stackrel{\mathrm{Burns}}{\to }{\mathrm{CO}}_2 \\ \mathrm{Coal}\left(\mathrm{Carbon}\right)\mathrm{Oxygen}\mathrm{Carbon}\mathrm{dioxide} \\ \left(\mathrm{sufficient}\right) \end{gathered}$$

(b) When coal (carbon) burns with inadequate amount of oxygen in the air, it produces carbon monoxide gas, which is toxic in nature. The balanced chemical equation for this reaction is given below​:
$$\begin{gathered} 2\mathrm{C}+{\mathrm{O}}_2\stackrel{\mathrm{Burns}}{\to }2\mathrm{CO} \\ \mathrm{Coal}\left(\mathrm{Carbon}\right)\mathrm{Oxygen}\mathrm{Carbon}\mathrm{mono}\mathrm{xide} \\ \left(\mathrm{insufficient}\right) \end{gathered}$$

(c) The type of reaction in each of the above cases is oxidation reaction. In both the cases, coal (carbon) reacts with oxygen and gets oxidised to form carbon dioxide in one case (a) and carbon monoxide in the other (b).

(d) Carbon monoxide is a toxic gas. It decreases the capability of blood to carry oxygen, which is necessary for the living beings to survive. Hence, ​carbon monoxide is a pollutant to the atmosphere.