Units

[Carolina Gomez 2G]

Why is the deltaH knot usually given in kilojoules while the deltaS knot is given in Joules. Is there a reason for them being given in different units?

[Leo Naylor 2F]

Delta S nought is usually given in joules per Kelvin, and the properties are given in these units to avoid having to use scientific notation because of very large or small numbers for enthalpy and entropy.

[Nathan Lao 2I]

I feel like it's more for convenience. Maybe because ΔH°usually deals with really high energy changes whereas ΔS° isn't as extreme.

[Rich Luong 1D]

It could be due to the fact that deltaH is a more dominant state variable than that of deltaS. What I mean is when dealing with enthalpy, a lot more energy is required for a certain process while entropy doesn't require so much energy for a certain disorder. It could also be due to the fact that entropy tends to be divided by Kelvin. Those are my thoughts, but I hope it helps!

[Giselle Granda 3F]

I am pretty sure kJ and J are interchangeable so I don't think it matters what the units are because you can always convert from kJ to J, or J to kJ and both answers will be equal to each other. I'm guessing those are just the common units but they can be changed if say, they ask for the final answer in J rather than kJ. Therefore, I doubt there's really any major significance behind using kJ vs J, because you can always convert from one to the other, someone else can correct me if I'm wrong though!

[Brennan McGurrr 3C]

The change in entropy is usually a lot smaller. It is more convenient to list them in joules. It just has to be converted when using them together.

[Susanna Givan 2B]

It probably has to do with the types of answers that we typically see with each variable and how large the answers typically are.