Question

Use standard free energies of formation to calculate ΔG∘ at 25∘C for each of the following reactions.

How do the values of ΔG∘ calculated this way compare to those calculated from ΔH∘ and ΔS∘? Which of the two methods could be used to determine how ΔG∘ changes with temperature?
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).

Answer 1

In general,

dG = Gfinal - Ginitial

for a reaction:

Greaction = Gproducts - Greactants

note that G products/reactants is actually the gibss free energy of formation of products/reactants

2.

dG relates as follows

dG° = dH° - T*dS°

then

dH and dS ar eimportant, if there is an increase in T, generally, we assume no changes in dH° and dS°, only in "T"

3.

if we wanted to calculate a change in T, it will be best to do it from the next equation

dG° = dH° - T*dS°

since we only need to change the absolute vlaue of T to get the new value of dG°