At the boiling point of water,$900 \ J/g$ of heat is exchanged. What is the increase in entropy in $J \ K^{-1} \ mol^{-1}$?

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 $J \, K^{-1} \, mol^{-1}$?

For a spontaneous process,

One mole of an ideal gas expands adiabatically and reversibly from its initial pressure to half of its initial pressure. What will be the value of $\Delta S$ in $J \ K^{-1} \ mol^{-1}$? $[ln 2 = 0.693$ and $R = 8.314 \ J \ mol^{-1} \ K^{-1}]$

What is the unit of $\Delta S_m^\circ$?

One mole of $NaCl$ $(s)$ on melting absorbed $30.5 \ kJ$ of heat and its entropy increased by $28.8 \ J \ K^{-1}$. The melting point of $NaCl$ is ............. $K$.