Entropy is a measure of .......

When $2 \ mol$ of an ideal gas $\left( C_{p,m} = \frac{5}{2} R \right)$ is heated from $300 \ K$ to $600 \ K$ at constant pressure,the change in entropy of the gas $\left( \Delta S \right)$ is:

For chemical reactions,the calculation of change in entropy is normally done:

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

Statement-$1$: For a process at equilibrium,the total entropy is maximum and the change in total entropy is zero.
Statement-$2$: For a reversible process,if the same amount of heat is supplied to a system at two different temperatures,then the entropy change is less at a lower temperature.

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: