Gibbs energy and equilibrium

2026 Re-NEET 1 question

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