Chemistry · The second law of thermodynamics: Spontaneity of processes, Delta S of the universe and Delta G of the system as criteria for spontaneity

At temperature of the reaction is Temperature

At temperature \( 1000^{\circ} \mathrm{C}, \Delta G \) of the reaction \( Z n O+C \rightarrow Z n+C O \) is Temperature

  • A. -ve
  • B. \( +v e \)
  • C. zero
  • D. nothing can be said

Step-by-step solution

The reaction ZnO(s) + C(s) → Zn(s) + CO(g) is endothermic (ΔH > 0) and has a positive entropy change (ΔS > 0) due to the formation of gas. At high temperature (1000°C), the TΔS term dominates, making ΔG = ΔH - TΔS negative. Thus, ΔG is negative (-ve).
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