$2 \, mol$ of zinc is dissolved in $HCl$ at $25 \, ^\circ C$. The work done in an open vessel is: (in $, kJ$)

The standard enthalpy of the decomposition of $N_2O_4$ to $NO_2$ is $58.04 \, kJ$ and standard entropy of this reaction is $176.7 \, J/K$. The standard free energy change for this reaction at $25 \, ^oC$ is $..... \, kJ$

For a reaction,$4 M (s) + n O_2 (g) \rightarrow 2 M_2 O_n (s)$,the free energy change is plotted as a function of temperature. The temperature below which the oxide is stable could be inferred from the plot as the point at which :

The criterion for a spontaneous process is

Consider the graph of $Gibbs$ free energy $G$ vs. Extent of reaction. The number of statement$(s)$ from the following which are true with respect to points $(a)$,$(b)$,and $(c)$ is $.................$
$A$. Reaction is spontaneous at $(a)$ and $(b)$
$B$. Reaction is at equilibrium at point $(b)$ and non-spontaneous at point $(c)$
$C$. Reaction is spontaneous at $(a)$ and non-spontaneous at $(c)$
$D$. Reaction is non-spontaneous at $(a)$ and $(b)$

Identify from the following the correct set of thermodynamic conditions for the reaction to be spontaneous at all temperatures.