Bond Enthalpies and the use of kJ

[Lauryn Jordan 1F]

When do you use kJ.mol, kj. Cº or just kj?

[Vasiliki G Dis1C]

kJ/mol is used for enthalpy of formation, and is for one substance, and you are always considering kJ needed for 1 mol of that substance.
kJ/C is used for heat capacity, since that is the energy (in the form of heat) needed to raise the temperature of an object by 1 degree C
kJ is used for standard reaction enthalpy when looking for an overall enthalpy change