Identify the correct statement regarding a spontaneous process: (a) Lowering of energy in the process is the only criterion for spontaneity.(b) For a spontaneous process in an isolated system, the change in entropy is positive. (c) Endothermic processes are never spontaneous.(d) Exothermic processes are always spontaneous ?

There are several equivalent alternative ways of representing the Second Law of Thermodynamics. One is in terms of entropy, S, a state function which is a measure of the molecular disorder of a system.

The law states that in the course of a spontaneous change, the entropy of an isolated system must increase. Note that since the universe is itself an isolated system, we can extend the law to any system within the universe by noting that for any spontaneous change, the total entropy of the universe must increase

(1) For a spontaneous process in an isolated system, the change in entropy is positive