For a process to be spontaneous,the total entropy change of the system and its surroundings must be $ \Delta S_{total} > 0 $. This condition is characteristic of which type of 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 $R = 8.314 \ J \ mol^{-1} \ K^{-1}]$

The enthalpy of vaporization of benzene is $+35.3 \ kJ/mol$ at its boiling point,$80^{\circ} C$. The entropy change in the transition of vapour to liquid at its boiling point is

The total amount of energy in the universe is fixed,but

The enthalpy change for the transition of liquid water to steam,$\Delta H_{vap} = 37.3 \ kJ \ mol^{-1}$ at $373 \ K$. The entropy change for the process is......$J \ mol^{-1} K^{-1}$.

Assertion : Water in liquid state is more stable than ice at room temperature.
Reason : Water in liquid form has higher entropy than ice.