Glycine, C₂H₅O₂N, is important for biological energy. The combustion reaction of glycine is described by the following thermochemical equation. 4C₂H₅O₂N(s) + 9O₂(g) → 8CO₂(g) + 10H₂O(l) + 2N₂(g) ΔH°_rxn = -3896 kJ/mol
What is the standard enthalpy of formation of solid glycine?

Question

Quizplus · Accepted Answer

The standard enthalpy of formation of a compound is the change in enthalpy when one mole of the compound is formed from its elements in their standard states. Using the given reaction and ΔH°rxn, the enthalpy of formation for glycine can be calculated. The enthalpy change for the reaction is given for 4 moles of glycine, so dividing -3896 kJ by 4 gives -974 kJ/mol for the reaction. Since the reaction is combustion, the enthalpy of formation of glycine is negative, and the closest value is -527.5 kJ/mol.

Glycine, C2H5O2N, Is Important for Biological Energy

Glycine, C₂H₅O₂N, Is Important for Biological Energy