The standard enthalpies of formation of $\mathrm{CO}_2(\mathrm{~g}), \mathrm{H}_2 \mathrm{O}(\mathrm{l})$ and glucose $(\mathrm{s})$ at $25^{\circ} \mathrm{C}$ are $-400 \mathrm{~kJ} / \mathrm{mol},-300 \mathrm{~kJ} / \mathrm{mol}$ and $-1300 \mathrm{~kJ} / \mathrm{mol}$, respectively. The standard enthalpy of combustion per gram of glucose at $25^{\circ} \mathrm{C}$ is