Reaction 1 is represented by the equation shown here. Reaction 1: $\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 \rightarrow 2\mathrm{CO}_2 + 2\mathrm{C}_2\mathrm{H}_5\mathrm{OH}$. The standard enthalpy changes of combustion, $\Delta H_c^\circ$, are: for $\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6$ it is $a$, and for $\mathrm{C}_2\mathrm{H}_5\mathrm{OH}$ it is $b$, in $\text{kJ mol}^{-1}$. Which expression gives the enthalpy change of reaction 1 correctly?
- A$a + b$
- B$a - b$
- C$a + 2b$
- D$a - 2b$