Observe the following reactions:
$I$. $CaCO_{3(s)} \rightarrow CaO_{(s)} + CO_{2(g)}$
$II$. $Cl_{2(g)} \rightarrow 2 Cl_{(g)}$
$III$. $H_2O_{(l)} \rightarrow H_2O_{(s)}$
Identify the reactions in which entropy increases.

Calculate $\Delta S_{total}$ for a certain reaction at $298 \ K$ if $\Delta H^{\circ} = -208.6 \ kJ$ and $\Delta S^{\circ} = -36 \ J \ K^{-1}$. (in $J \ K^{-1}$)

At $1 \ atm$ pressure,if $\Delta S_{\text{vap}} = 75 \ J \ K^{-1} \ mol^{-1}$ and $\Delta H_{\text{vap}} = 30 \ kJ \ mol^{-1}$,what will be the boiling point of the liquid in $K$?

In which of the following processes does entropy increase?
$A$. $A$ liquid evaporates to vapour.
$B$. Temperature of a crystalline solid is lowered from $130 \ K$ to $0 \ K$.
$C$. $2 NaHCO_{3(s)} \rightarrow Na_2CO_{3(s)} + CO_{2(g)} + H_2O_{(g)}$
$D$. $Cl_{2(g)} \rightarrow 2 Cl_{(g)}$
Choose the correct answer from the options given below:

The second law of thermodynamics states that in a cyclic process:

For an endothermic reaction $A \rightarrow B$ to occur spontaneously at a constant temperature $T$,the entropy change $\Delta S$ must be: