| Date | November 2011 | Marks available | 2 | Reference code | 11N.3.sl.TZ0.C1 |
| Level | SL | Paper | 3 | Time zone | TZ0 |
| Command term | Explain | Question number | C1 | Adapted from | N/A |
Question
The Industrial Revolution was the result of large-scale extraction of iron from its ore and had significant impact worldwide.
In a blast furnace, a large volume of air is introduced under pressure near the bottom while a mixture of limestone, coke and iron(III) oxide is introduced at the top.
State the equation for the reaction of coke with air in the blast furnace.
The product formed in part (i) reacts with coke to produce carbon monoxide. Explain, giving an equation, why this reaction is important in the extraction of iron.
Markscheme
\({\text{C(s)}} + {{\text{O}}_2}{\text{(g)}} \to {\text{C}}{{\text{O}}_2}{\text{(g)}}\);
Ignore state symbols.
CO acts as a reducing agent / reaction is endothermic/cools (this part of) furnace;
\({\text{C}}{{\text{O}}_2}{\text{(g)}} + {\text{C(s)}} \to {\text{2CO(g)}}/{\text{F}}{{\text{e}}_2}{{\text{O}}_3}{\text{(s)}} + {\text{3CO(g)}} \to {\text{2Fe(l)}} + {\text{3C}}{{\text{O}}_2}{\text{(g)}}\);
Ignore state symbols.
Examiners report
Generally the equation for the reaction of coke with air was given correctly.
The correct equation for the reaction of \({\text{C}}{{\text{O}}_2}\) with coke was sometimes missing
