Which of the following statements is true? The entropy of the universe

Match the following processes with their corresponding entropy changes:

$a$. Liquid to vapor conversion	$1$. $\Delta S = 0$
$b$. Reaction not spontaneous at any temperature,$\Delta H = (+)$	$2$. $\Delta S = (+)$
$c$. Reversible expansion of an ideal gas	$3$. $\Delta S = (-)$

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 $25\,^oC$?

Standard entropy of $X_2, Y_2$ and $XY_3$ are $60, 40$ and $50 \ J \ K^{-1} \ mol^{-1},$ respectively. For the reaction,$\frac{1}{2}X_2 + \frac{3}{2}Y_2 \to XY_3, \ \Delta H = -30 \ kJ,$ to be at equilibrium,the temperature will be ............... $K$.

Which of the following has the highest entropy per mole?

$30.4 \, kJ$ of heat is required to melt one mole of sodium chloride and the entropy change at the melting point is $28.4 \, J \, K^{-1} \, mol^{-1}$ at $1 \, atm$. The melting point of sodium chloride is $........... \, K$ (Nearest Integer).