Solid Z dissolves non-spontaneously below 280 K but dissolves spontaneously above 310 K

CHEMISTRY · Single correct · A Level · Chemistry · Thermodynamics · Thermodynamics

Problem

Solid Z dissolves non-spontaneously below 280 K but dissolves spontaneously above 310 K, and its ΔH° is temperature-independent. Which set of thermodynamic conditions is most consistent with this behavior? (a) ΔH∘>0\Delta H^{\circ} > 0 and ΔS∘>0\Delta S^{\circ} > 0, with ΔH∘ΔS∘<280 K\dfrac{\Delta H^{\circ}}{\Delta S^{\circ}} < 280\,\text{K} (b) ΔH∘>0\Delta H^{\circ} > 0 and ΔS∘>0\Delta S^{\circ} > 0, with ΔH∘ΔS∘\dfrac{\Delta H^{\circ}}{\Delta S^{\circ}} between 280 K280\,\text{K} and 310 K310\,\text{K} (c) ΔH∘<0\Delta H^{\circ} < 0 and ΔS∘<0\Delta S^{\circ} < 0, with ∣ΔH∘ΔS∘∣\left|\dfrac{\Delta H^{\circ}}{\Delta S^{\circ}}\right| between 280 K280\,\text{K} and 310 K310\,\text{K} (d) ΔH∘>0\Delta H^{\circ} > 0 and ΔS∘<0\Delta S^{\circ} < 0, regardless of magnitude

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