What conditions must be satisfied for a chemical reaction to occur spontaneously?

• A. The change in entropy (ΔS) must be negative.
• B. The change in enthalpy (ΔH) must be positive.
• C. The Gibbs free energy change (ΔG) must be positive.
• D. The Gibbs free energy change (ΔG) must be negative.

Answer: (D)