The standard enthalpy changes for combustion of carbon, hydrogen and methanol are listed below. $\text{C}(s)+\text{O}_2(g)\rightarrow\text{CO}_2(g)\quad\Delta H_c^\circ=-394\,\text{kJ mol}^{-1}$ $\text{H}_2(g)+\frac{1}{2}\text{O}_2(g)\rightarrow\text{H}_2\text{O}(l)\quad\Delta H_c^\circ=-286\,\text{kJ mol}^{-1}$ $\text{CH}_3\text{OH}(l)+\frac{3}{2}\text{O}_2(g)\rightarrow\text{CO}_2(g)+2\text{H}_2\text{O}(l)\quad\Delta H_c^\circ=-726\,\text{kJ mol}^{-1}$ Which expression represents the standard enthalpy change of formation of methanol, in $\text{kJ mol}^{-1}$?
- A$-394 + (-286) - (-726)$
- B$-394 + (-286\times2) - 726$
- C$-394 + (-286\times2) - (-726)$
- D$-726 - (-394) - (-286\times2)$