How does entropy effect enthalpy?
Both are energy terms: enthalpy reflecting the stability of a substance as a result of its bonding, and entropy reflecting the degrees of freedom or amount of disorder in a substance.
Both entropy and enthalpy have a role to play in determining whether a reaction will be feasible or not. They are combined in a quantity referred to as free energy. The free energy change is given by the enthalpy change, minus the entropy change times the absolute temperature. It the free energy change is negative, the reaction is feasible.