For a process,entropy change of a system is expressed as

$A$ container is divided into two compartments by a removable partition as shown below:
In the first compartment,$n_{1}$ moles of ideal gas $He$ is present in a volume $V_{1}$. In the second compartment,$n_{2}$ moles of ideal gas $Ne$ is present in a volume $V_{2}$. The temperature and pressure in both the compartments are $T$ and $p$,respectively. Assuming $R$ is the gas constant,the total change in entropy upon removing the partition when the gases mix irreversibly is:

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 $J \ K^{-1}$)

For an isolated system,$\Delta U = 0,$ what will be $\Delta S?$

The change in entropy is negative for which of the following processes?

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.