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

1 Answer
Jul 18, 2016

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

Explanation:

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#.