A. If there is an increase in the number of gas molecules, then AS = 0.
B. The change in entropy cannot be predicted in a gas reaction.
C. If there is an increase in the number of gas molecules, then AS> 0.
D. If there is an increase in the number of gas molecules, then AS<0.

Answerδh > 0explanationc₆h₆  (s)  → c₆h₆ (l)if you are changing it from a solid to a liquid, you are pretty much melting the solid. this requires heat energy. therefore, the reaction is endothermic (takes in energy); the system enthalpy increases as the reaction proceeds: δh > 0.

Ibelieve the answer 4 moles