The standard enthalpy of formation of glucose is -1273.3kJ/mol, and for carbon dioxide it is -393.5kJ/mol, and for water -285.8 kJ/mol. What is the standard enthalpy of combustion of glucose, C6H12O6?
The reaction equation has the form C6H12O6 + xO2 -> yCO2 + zH2O. Balancing carbons, y=6. Balancing hydrogens, z=6, so by balancing oxygen atoms, x=6. Then we use a Hess's law cycle (to be shown during interview) to find that the enthalpy of combustion is -(-1273.3kJ/mol)+(-6x-393.5kJ/mol+-6x-285.8kJ/mol) = -2802.5kJ/mol.
AC
Related Chemistry A Level answers
All answers ▸How does a change in temperature affect the Kc value when the forward reaction is exothermic?
Explain why the enthalpy of lattice dissociation of potassium oxide is less endothermic than that of sodium oxide.
what is a simple test to detect the presence of a carbonyl and to identify it?
Calculate the PH of 32 mmol of HCl in 75cm^3 solution. Assume HCl fully dissociates.