The following reaction occurs in the Blast furnance where iron ore is reduced to iron metal
$\mathrm{Fe}_2 \mathrm{O}_{3(\mathrm{~s})}+3 \mathrm{CO}_{(\mathrm{g})} \rightleftharpoons \mathrm{Fe}_{(\mathrm{l})}+3 \mathrm{CO}_{2(\mathrm{~g})}$ Using the Le-chatelier's principle, predict which one of the following will not disturb the equilibrium.