JAMB Chemistry 2016 Paper

Concept:The waste gas from the blast furnace is the mixture of gases produced from the air blast and the reduction of iron ore.Explanation:Hot air is blown into the blast furnace.Nitrogen, $N_2$, from the air does not react and escapes with the furnace gas.Coke burns in oxygen to form carbon dioxide: $C + O_2 \to CO_2$.Carbon dioxide is reduced by hot coke to carbon monoxide: $CO_2 + C \to 2CO$.Carbon monoxide reduces iron(III) oxide in the ore, producing more $CO_2$.Hence, the furnace waste gas is a mixture of nitrogen, carbon monoxide, and carbon dioxide.Answer:The correct mixture is $N_2$, $CO$, and $CO_2$, i.e. Option C.