ΔG= ΔH -TΔS

[Tamera Scott 1G]

Should you convert all the units into kJ/mol in the beginning of the problem or can you wait until the end when solving for ΔG with ΔG= ΔH -TΔS?

[Camille Marangi 2E]

As long as both the enthalpy and entropy are joules/mol, you can wait until after calculations to convert to KJ/mol.

[Vincent Li 4L]

In most cases, if you have to calculate change in entropy and change in enthalpy separately before using the Gibbs Free Equation, entropy tends to be in J/mol whereas enthalpy tends to be in kJ/mol. When calculating each of the constituent thermodynamic values, it doesn't really matter if it's in J/mol or kJ/mol as long as it's consistent. When using the actual delta G equation, it is important, however, to either convert both to kJ/mol or J/mol before getting the final answer.