Mean Bond Enthalpies

Question 1

Bond dissociation energy (gaseous compound)

Answer 1

Energy required to break a 1 mole of a specific covalent bond in a gaseous state

Question 2

Enthalpy change equation

Answer 2

Enthalpy change = Σ(reactant bonds broken) - Σ(product bonds made)

Question 3

Explain why values from mean bond enthalpy calculations differ from those determined using Hess’s law

Answer 3

Hess’s law - bond enthalpy for that specific reaction
Mean bond enthalpy - bond enthalpy over several different reactions.

Question 4

ethane-1,2-diamine formula

Answer 4

C 2 H 8 N 2