9.55 vs 9.57

[Nina Gautam 1K]

In homework problem 9.55, we are asked to write a balanced equation for the formation of molecules and calculate standard reaction Gibbs free energy, entropy, and enthalpy. In the solutions manual, fraction coefficients are used to yield exactly one mole of product.
In problem 9.57, however, we are also asked to calculate the standard reaction Gibbs free energy, entropy, and enthalpy of the given equations, but the solution manual keeps the coefficients whole.
When are we supposed to keep coefficients whole and when are we supposed to divide them so that there is only one mol of product? How does this work for multiple products?
Thanks!

[Gevork 2E]

Hi,

So it really depends on the question. If the question is asking for the entire reaction, then you should be aware of all the coefficients and make sure that you are using them. Typically we divide when it asks for a specific molecule.

Here is an example:
2A + B --> C

If the question asks for the reaction, use the coefficients (notice 2 on A)

Now, if the question asks "per mol of A", then you would divide everything by two to yield one mol of A

Hope this was helpful.