question_answer

An exothermic reaction \[A\xrightarrow{\,}B\] is spontaneous in the backward direction. What will be the sign of\[\Delta S\] for the forward reaction?

Answer:

              Backward reaction will be endothermic. Thus, energy factor opposes the backward reaction. As backward reaction is spontaneous, randomness factor must favour, i.e., \[\Delta S\] will be +ve for backward reaction or it will be -ve for forward reaction.