A Closed System of Constant Internal Energy and Volume

1 A Closed System of Constant Internal Energy and Volume 

The rate of entropy change, dS/dt, for a closed system is given by  

The first term, dS /dt, r resents the variation of entropy with time due to reversible changes in Ae system and the second, dSg /dt, the rate of entropy generation due to irreversible changes in it. 

To determine dS /dt, let us assume that the system is undergoing a reversible change and apply the first law to it  

Since dSg is always positive, the entropy will continue to increase until the system attains equilibrium, where it reaches its maximum value  

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