When is a reaction spontaneous?

For the vaporization of water at $1 \ atm$ pressure,the values of $\Delta H$ and $\Delta S$ are $40.63 \ kJ/mol$ and $108.8 \ J/K \cdot mol$ respectively. At what temperature $(K)$ will the change in Gibbs energy $(\Delta G)$ be zero (in $.4$)?

What is the value of $\Delta G$ for a water system in an environment with a temperature of $100 \ K$?

If an endothermic reaction is non-spontaneous at the freezing point of water and becomes feasible at its boiling point,then:

What happens during a spontaneous process?

For the melting of $3 \ mol$ of ice at $0^o \text{C}$,$\Delta G = \dots \dots$