# Explain with equation how does entropy of a close system increase?

420 Points
13 years ago

Dear Ranjan

In the absence of any friction, then the net entropy change is 0.

For any real process, there is friction. Entropy is transferred with heat transfer, and the direction of entropy transfer is the same as that of heat transfer. So, any time heat is transferred into the system, the entropy of the system increases. Any time heat is transferred out of the system, the entropy of the system decreases. Heat transfer out is the only means of decreasing system entropy of a closed system. For an open system, entropy can be transferred out with energy transfer out, and with mass transfer out.

so any real process increases the entropy of the system. But whether the entropy of the system itself increases or decreases is dependent on the heat transfer.

For an isolated system, there is no heat transfer, there is no means of reducing the entropy of the system. Which means that for any real process in an isolated system, the entropy of the system increases, and the energy available to do work decreases.

All the best.

AKASH GOYAL

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