Under what conditions does a reaction always occur spontaneously?

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?

For water,the value of $\Delta H_{vap}$ is $40.73 \, kJ \, mol^{-1}$ and the value of $\Delta S_{vap}$ is $109 \, J \, K^{-1} \, mol^{-1}$. At what temperature will water be in equilibrium with its vapor?

For a reaction,$\Delta H = -40 \, kJ$ and $\Delta S = -50 \, J/K$. At what temperature range will it change from spontaneous to non-spontaneous?

The condition for a reaction to occur spontaneously is

For a spontaneous process,which of the following conditions must be met?