The enthalpy of fusion of water is $1.435 \ kcal/mol$. The molar entropy change for the melting of ice at $0 \ ^\circ C$ is

Which of the following processes is associated with an increase in entropy?
$(I)$ Melting of a solid
$(II)$ Mixing of gases
$(III)$ Compression of a gas
$(IV)$ Expansion of a gas

$A$ container has a hydrogen and oxygen mixture in a ratio of $4 : 1$ by weight. When these gases are mixed,which of the following occurs?

Let us consider a reversible reaction at temperature,$T$. In this reaction,both $\Delta H$ and $\Delta S$ were observed to have positive values. If the equilibrium temperature is $T_e$,then the reaction becomes spontaneous at:

At $25\,^oC$ and $1\,atm$ pressure,mercury reacts with chlorine to form mercurous chloride: $2Hg + Cl_2 \to Hg_2Cl_2; \Delta H = -31.3\,kcal$. What is the entropy change of the reaction at $25\,^oC$?

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