Under isothermal and reversible conditions,the term "free energy" in thermodynamics signifies

$\Delta H$ and $\Delta S$ for a reaction are $+30.0 \ kJ \ mol^{-1}$ and $0.06 \ kJ \ K^{-1} \ mol^{-1}$ at $1 \ atm$ pressure. The temperature at which free energy change is equal to zero and the nature of the reaction below this temperature are:

The values of $\Delta H$ and $\Delta S$ for the reaction,$C_{(graphite)} + CO_{2(g)} \rightarrow 2CO_{(g)}$ are $170 \ kJ$ and $170 \ J \ K^{-1}$ respectively. This reaction will be spontaneous at temperatures greater than ............ $K$.

When is a reaction spontaneous?

What will be the value of $\Delta G$ for the melting of ice at $283 \ K$?

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