| Date | May 2015 | Marks available | 1 | Reference code | 15M.3.sl.TZ2.10 |
| Level | SL | Paper | 3 | Time zone | TZ2 |
| Command term | State | Question number | 10 | Adapted from | N/A |
Question
Iron is extracted from its ore by reduction in a blast furnace.
State an equation for the reaction by which iron (III) oxide, Fe2O3, is reduced to iron in the blast furnace.
Markscheme
\({\text{F}}{{\text{e}}_2}{{\text{O}}_3}{\text{(s)}} + {\text{3CO(g)}} \to {\text{2Fe(l)}} + {\text{3C}}{{\text{O}}_2}{\text{(g)}}/{\text{F}}{{\text{e}}_2}{{\text{O}}_3}{\text{(s)}} + {\text{3}}{{\text{H}}_2}{\text{(g)}} \to {\text{2Fe(l)}} + {\text{3}}{{\text{H}}_2}{\text{O(g)}}\) /
\({\text{2F}}{{\text{e}}_2}{{\text{O}}_3}{\text{(s)}} + {\text{3C(s)}} \to {\text{4Fe(l)}} + {\text{3C}}{{\text{O}}_2}{\text{(g)}}/{\text{F}}{{\text{e}}_2}{{\text{O}}_3}{\text{(s)}} + {\text{3C(s)}} \to {\text{2Fe(l)}} + {\text{3CO(g)}}\);
Ignore state symbols.
Examiners report
It was pleasing to see a good number of correctly balanced equations here. The precise explanation of how alloying of steel affects physical properties was rarely seen. The correct description of how quenched steel is tempered was rarely seen with the most common answer being heated and rapidly cooled.
