Date | November 2012 | Marks available | 1 | Reference code | 12N.1.sl.TZ0.16 |
Level | SL | Paper | 1 | Time zone | TZ0 |
Command term | Question number | 16 | Adapted from | N/A |
Question
Using the equations below:
\[\begin{array}{*{20}{l}} {{\text{C(s)}} + {{\text{O}}_{\text{2}}}{\text{(g)}} \to {\text{C}}{{\text{O}}_{\text{2}}}{\text{(g)}}}&{\Delta {H^\Theta } = - 390{\text{ kJ}}} \\ {{{\text{H}}_2}{\text{(g)}} + \frac{1}{2}{{\text{O}}_2}{\text{(g)}} \to {{\text{H}}_2}{\text{O(l)}}}&{\Delta {H^\Theta } = - 286{\text{ kJ}}} \\ {{\text{C}}{{\text{H}}_4}{\text{(g)}} + {\text{2}}{{\text{O}}_2}{\text{(g)}} \to {\text{C}}{{\text{O}}_2}{\text{(g)}} + {\text{2}}{{\text{H}}_2}{\text{O(l)}}}&{\Delta {H^\Theta } = - 890{\text{ kJ}}} \end{array}\]
what is \({\Delta {H^\Theta }}\), in kJ, for the following reaction?
\[{\text{ C(s)}} + {\text{2}}{{\text{H}}_2}{\text{(g)}} \to {\text{C}}{{\text{H}}_4}{\text{(g)}}\]
A. –214
B. –72
C. +72
D. +214
Markscheme
B
Examiners report
The examination normally uses kJ when an equation is given as here; if it were to quote a value, say, for the heat of formation of a compound, then this would be given in kJ\(\,\)mol–1.