For a spontaneous change,free energy change $\Delta G$ is

For an irreversible process occurring at constant $T$ and $P$,where only pressure-volume work is involved,which condition for entropy change $(\Delta S)$ and Gibbs free energy change $(\Delta G)$ is satisfied?

The standard enthalpy and standard entropy of decomposition of $N_2O_4$ to $NO_2$ are $55.0 \ kJ \ mol^{-1}$ and $175.0 \ J \ K^{-1} \ mol^{-1}$ respectively. The standard free energy change for this reaction at $25 ^{\circ}C$ in $J \ mol^{-1}$ is $............$ $(Nearest \ integer)$.

For a reaction to be spontaneous at all temperatures, the values of enthalpy change $\Delta H$ and entropy change $\Delta S$ should be:

Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However,the reaction is spontaneous at the boiling point of water. Choose the correct option.

For the reaction $CaCO_{3(s)} \to CaO_{(s)} + CO_{2(g)}$,given $\Delta H^o = 178.3 \, kJ$ and $\Delta S^o = 160 \, J \cdot K^{-1}$. At what temperature will the reaction become spontaneous?