Entropy

Entropy(S) is a thermodynamic state function that measures the degree of energy dispersal or randomness/disorder of a system.

Unit:-J K-¹

For Specific entropy 

Unit:- J Kg K-¹

  ●                        dS=dQ/T

For reversible process ds=0

For irreversible process ds>0

Examples:-

●Ice melting → entropy increases.

●Water evaporating → entropy increases.

●Gas expanding freely → entropy increases.

●Heat naturally flowing from hot to cold → total entropy increases.