Chemistry · May / June 2019 · Paper 11 · Question 17

The table shows the energy released by the complete combustion of some compounds. | compound | formula | $M_r$ | $\Delta H$ in kJ / mol | |---|---|---|---| | benzene | C$_6$H$_6$ | 78 | –3270 | | heptane | C$_7$H$_{16}$ | 100 | –4800 | | octane | C$_8$H$_{18}$ | 114 | –5510 | | propane | C$_3$H$_8$ | 44 | –2200 | Which compound releases the least energy when 1 g is completely burned?

1. Abenzene
2. Bheptane
3. Coctane
4. Dpropane

As printed in the paper