Give the mathematical equation for entropy change.

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 $(R = 2 \ cal / mol \cdot K)$ :-

For the reaction $NH_4Cl_{(s)} \rightarrow NH_{3(g)} + HCl_{(g)}$,the entropy change is ...... .

The enthalpy change for the transition of liquid water to steam at $373 \, K$ is $40.8 \, kJ \, mol^{-1}$. What is the $\Delta S$ for the process in $J \, K^{-1} \, mol^{-1}$?

The $\Delta S$ for the vaporisation of $1 \ mol$ of water is $88.3 \ J/mol \ K$. The value of $\Delta S$ for the condensation of $1 \ mol$ of vapour will be.......$ J/mol \ K$

For a process,entropy change of a system is expressed as