One mole of water at $100\,^{\circ}C$ is converted into steam at $100\,^{\circ}C$ at a constant pressure of $1\,atm$. The change in entropy is [heat of vaporisation of water at $100\,^{\circ}C = 540\,cal/g$].

The unit of entropy is

Assertion : Entropy of ice is less than water.
Reason : Ice has a cage-like structure.

Considering entropy $(S)$ as a thermodynamic parameter,the criterion for the spontaneity of any process is

Find the change in entropy for the fusion of $1 \, mol$ of ice in $J \, K^{-1} \, mol^{-1}$. The melting point of water is $273 \, K$ and the molar enthalpy of fusion for water is $6.0 \, kJ \, mol^{-1}$.

One mole of an ideal diatomic gas $(C_V = 5 \ cal)$ was transformed from initial $25 \ ^{\circ}C$ and $1 \ L$ to the state when temperature is $100 \ ^{\circ}C$ and volume $10 \ L$. The entropy change of the process can be expressed as $(R = 2 \ cal / mol \cdot K)$ :-