Are chemical reactions always spontaneous when $DeltaH$ is negative and $DeltaS$ is negative?

Question

7422 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-07-18T22:23:34

No. A reaction cannot be spontaneous under these conditions unless Temperature is low enough.

The equation for spontaneity is $DeltaG$ = $DeltaH$ - $TDeltaS$

A reaction can only occur when the value of $DeltaG$ is negative.

If the reaction is nonspontaneous, it can be coupled with a spontaneous reaction to give an overall - $DeltaG$ .

Are chemical reactions always spontaneous when DeltaHDeltaH is negative and DeltaSDeltaS is negative?