For a reaction $\Delta H = -30 \ kJ$ and $\Delta S = -45 \ J \ K^{-1}$,at what temperature does the reaction change from spontaneous to non-spontaneous (in $K$)?

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 :

When $\Delta H_{vap} = 30 \ kJ \ mol^{-1}$ and $\Delta S_{vap} = 75 \ J \ mol^{-1} \ K^{-1}$,then the temperature of vapour,at one atmosphere is . . . . $K$.

Assertion: Many endothermic reactions that are not spontaneous at room temperature become spontaneous at high temperature.
Reason: Entropy of the system increases with increase in temperature.

In the conversion of limestone to lime,$CaCO_{3(s)} \rightarrow CaO_{(s)} + CO_{2(g)}$,the values of $\Delta H^{\circ}$ and $\Delta S^{\circ}$ are $+179.1 \ kJ \ mol^{-1}$ and $160.2 \ J \ K^{-1} \ mol^{-1}$ respectively at $298 \ K$ and $1 \ bar$. Assuming that $\Delta H^{\circ}$ and $\Delta S^{\circ}$ do not change with temperature,the temperature above which the conversion of limestone to lime will be spontaneous is ........... $K$.

For a process occurring at constant temperature and pressure,which of the following is true at equilibrium?