The heat of combustion of carbon to $C{O}_2$ is -393.5  kJ/mol. The heat released upon formation of 35.2 g of $C{O}_2$ from carbon and oxygen gas is

In NEET, AIPMT 2015 Re-exam fourth option is -315 kJ but the correct answer is -315 kJ/mole. NTA gives none as a answer key because unit is different from the correct answer. Correct answer has kJ/mole unit not kJ.

Given,

${\mathrm{C}}_{\left(\mathrm{s}\right)}+{\mathrm{O}}_{2( \mathrm{g})}⟶{\mathrm{CO}}_{2( \mathrm{g})},\Delta H=-393.5 \mathrm{kJ}/\mathrm{mol}$

Amount of heat released on formation of $44 \mathrm{g} {\mathrm{CO}}_2=393.5 \mathrm{kJ}/\mathrm{mole}$

$\therefore \text{ Amount of heat released on formation of }35.2 \mathrm{g} {\mathrm{CO}}_2$

$\mathrm{Heat} \mathrm{released}=-\frac{393.5 \mathrm{kJ}/\mathrm{mole}}{44 \mathrm{g}}\times 35.2 \mathrm{g}$

$=-315 \mathrm{kJ}/\mathrm{mole}$