question_answer

Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is:                                                                                                                                                           [AIPMT (S) 2004]

A)  \[\Delta \,{{S}_{\text{system}}}+\Delta {{S}_{\text{surroundings}}}>0\]

B)  \[\Delta \,{{S}_{\text{system}}}-\Delta {{S}_{\text{surroundings}}}>0\]

C)  \[\Delta \,{{S}_{\text{system}}}>0\] only

D)  \[\Delta {{S}_{\text{surroundings}}}>0\] only

Correct Answer: A

Solution :

For spontaneous process, must be positive. In reversible process

Hence, system is present in equilibrium.

(i.e., it is not spontaneous process)

While in irreversible process

Hence, in the process is positive.