The signs of DG, DH, and DS at 25°C are shown in the table below for three reactions.

Question

Reaction DG DH DS
I - + +
II - - +
III - - -

Which reaction or reactions should go in the REVERSE direction at high temperature?

Answer 1

Here is what I did for #1.
delta G = delta H - T*delta S
delta G -
delta H +
delta S +
For high T, -Tdelta S is more negative which makes delta G more negative. Since it is already negative, raising T won't change the direction.
I think reaction ii and iii are done the same.