Date | May 2013 | Marks available | 1 | Reference code | 13M.1.hl.TZ2.15 |
Level | HL | Paper | 1 | Time zone | TZ2 |
Command term | Determine | Question number | 15 | Adapted from | N/A |
Question
Enthalpy changes of reaction are provided for the following reactions.
\[\begin{array}{*{20}{l}} {{\text{2C(s)}} + {\text{2}}{{\text{H}}_2}{\text{(g)}} \to {{\text{C}}_2}{{\text{H}}_4}{\text{(g)}}}&{\Delta {H^\Theta } = + {\text{52 kJ}}\,{\text{mo}}{{\text{l}}^{ - 1}}} \\ {{\text{2C(s)}} + {\text{3}}{{\text{H}}_2}{\text{(g)}} \to {{\text{C}}_2}{{\text{H}}_6}{\text{(g)}}}&{\Delta {H^\Theta } = - {\text{85 kJ}}\,{\text{mo}}{{\text{l}}^{ - 1}}} \end{array}\]
What is the enthalpy change, in \({\text{kJ}}\,{\text{mo}}{{\text{l}}^{ - 1}}\), for the reaction between ethene and hydrogen?
\[{{\text{C}}_2}{{\text{H}}_4}{\text{(g)}} + {{\text{H}}_2}{\text{(g)}} \to {{\text{C}}_2}{{\text{H}}_6}{\text{(g)}}\]
A. –137
B. –33
C. +33
D. +137
Markscheme
A