Provide the mathematical equation for entropy change.

The value of entropy of the universe is

For a spontaneous process,

One mole of ice is converted into water at $1 \ atm$ and $273 \ K$. The entropies of $H_2O_{(s)}$ and $H_2O_{(\ell)}$ are $38.2$ and $60.01 \ J \ mol^{-1} \ K^{-1}$ respectively. The enthalpy change for the conversion is ...... $J \ mol^{-1}$.

For a spontaneous process,the correct statement is

Calculate the sign of $\Delta S$ for the melting of ice at $275 \ K$.