Burning the coal is represented as ${\mathrm{C}}_{\left(\mathrm{s}\right)}+{\mathrm{O}}_{2\left(\mathrm{g}\right)}⟶{\mathrm{CO}}_{2\left(\mathrm{g}\right)}.$
The rate of this reaction is increased by

In a reaction $\mathrm{A}+\mathrm{B}\rightleftharpoons \mathrm{C}+\mathrm{D},$ Le Chatelier's principle asserts that an equilibrium between $\mathrm{A}$ and $\mathrm{B}$ producing $\mathrm{C}$ and $\mathrm{D}$ can be shifted towards $\mathrm{C}$ and $\mathrm{D}$ by
(i) increasing the concentration of $\mathrm{A}$ or $\mathrm{B}$

(ii)increasing the concentration of $\mathrm{C}$ or $\mathrm{D}$

(iii) decreasing the concentration of $\mathrm{A}$ or $\mathrm{B}$