Thermodynamics

A protein undergoes reversible thermal denaturation from its initial state $\mathbf{N}$ to denatured state $\mathbf{D}$ according to $\mathbf{N} \rightleftharpoons \mathbf{D}$. At $60^{\circ} \mathrm{C}$, the concentrations of both $\mathbf{N}$ and $\mathbf{D}$ are equal at equilibrium, and the standard enthalpy change of denaturation is $666 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The standard entropy change $\Delta \mathrm{S}^{\circ}$ in $\mathrm{kJ} \mathrm{K}^{-1} \mathrm{~mol}^{-1}$ ) of the protein upon denaturation at $60^{\circ} \mathrm{C}$ is closest to