Question

The combustion of glucose, C6 H12 O6 (s), produces carbon dioxide, CO2 (g), and water, H2 O(g), according to the equation below.

Upper C subscript 6 upper H subscript 12 upper O subscript 6 (s) plus 6 upper O subscript 2 (g) right arrow 6 upper C upper O subscript 2 (g) plus 6 upper H subscript 2 upper O (l).

The enthalpy of the reaction is –2,840 kJ. What is the heat of combustion, per mole, of glucose?
–2,840 kJ/mol
–473.3 kJ/mol
473.3 kJ/mol
2,840 kJ/mol

Answer 1

The enthalpy given (−2,840 kJ) is for the reaction as written, which consumes 1 mol of glucose. Therefore the heat of combustion per mole of glucose is −2,840 kJ/mol.