[Campbell Biology P.196] According to the provided text, for a chemical reaction to be spont... | Practice Question

According to the provided text, for a chemical reaction to be spontaneous, what must be true about its Gibbs free-energy change ΔG ?

  • A: ΔG must be positive.
  • B: ΔG must be zero.
  • C: ΔG must be negative.
  • D: ΔG's sign depends only on the change in enthalpy (ΔH).

Explanation

The text explicitly states: 'More than a century of experiments has shown that only processes with a negative ΔG are spontaneous.' This means a reaction is spontaneous if and only if its Gibbs free-energy change is negative.