Under what conditions is a chemical reaction always spontaneous?
1) When both the reaction enthalpy change and reaction entropy change are positive.
2) When both the reaction enthalpy change and reaction entropy change are negative.
3) When the reaction entropy change is positive (the reaction enthalpy change doesn't matter).
4) When the reaction enthalpy change is positive and the reaction entropy change is negative.
5) When the reaction enthalpy change is negative and the reaction entropy change is positive.
