Delta S

[Ruby 1l]

Can delta S be equal to zero? If delta H is 0 does that automatically mean that Gibbs free energy will be negative?

[marina niland 3b]

Delta S can be equal to zero, if there is no change in entropy.

Even if H is 0, G is still able to be positive.
The equation is:
deltaG=deltaH-T*deltaS

If DeltaS were to be negative, than the negative would cancel with the subtraction and become positive, making DeltaG positive.

[Melody L Lehman 2C]

Change in entropy equals zero when the reaction is reversible (or there is no net change in entropy).

The equation ∆G = ∆H - T∆S tells us ∆G can still be negative if ∆H = 0 if ∆S is positive. If ∆H = 0 and ∆S is negative, the negative in -T will cancel out the negative ∆S and the ∆G will be positive.