An irreversible process occurring isothermally in an isolated system leads to

For a reversible expansion of $5 \, \text{mol}$ of an ideal gas at $27 \, ^\circ\text{C}$ from a volume of $8 \, \text{dm}^3$ to $80 \, \text{dm}^3$,the change in entropy is ...... $J \, K^{-1}$.

During which of the following processes does entropy decrease?
$(A)$ Freezing of water to ice at $0^{\circ} C$
$(B)$ Freezing of water to ice at $-10^{\circ} C$
$(C)$ $N_{2(g)} + 3H_{2(g)} \rightarrow 2NH_{3(g)}$
$(D)$ Adsorption of $CO_{(g)}$ on a lead surface
$(E)$ Dissolution of $NaCl$ in water

In which of the following reactions,standard reaction entropy change $(\Delta S^o)$ is positive and standard Gibb's energy change $(\Delta G^o)$ decreases sharply with increasing temperature?

Change in entropy is positive for

What is the entropy of vaporisation of water at $100\,^{\circ}C$,if the molar heat of vaporisation is $9710\,cal/mol$?