Units of entropy [ENDORSED]

[Cowasjee_Sanaea_3E]

I had always thought that the units for entropy was: joules/moles x kelvin
But is it possible for it to be just:
joules/kelvin?

[Nerissa_Low_2F]

Yes it is possible. Entropy can be equal to q/T, and the units for q is Joules and Kelvin for T, so the units of your answer can be Joules/Kelvin.

[Rochelle Ellison 2H]

The same rules of units apply as when we were calculating enthalpy. If the moles cancel out, then your final answer should not be J/(K * mol) unless the problem is asking for your answer per mole in which case you would divide your answer by the number of moles given in the problem or the chemical equation. If you follow your units throughout the problem you should end up with the right units in your answer.

[Aiden_Hsu_1M]

If the problem asks for entropy per unit of a substance, it would be J/(K*mol) or J/(K*mol) if it's per unit mass. Otherwise you can probably assume they just want the answer in J/K.