Question

Question 16 of 25According to the Gibbs free energy equation, AG = AH-TAS, when is areaction always spontaneous?A. When AH and AS are both positiveB. When AH is negative and AS is positiveC. When AH is positive and AS is negativeD. When AH and AS are both negativeSUBMIT

Answer 1

B. When ΔH is negative and ΔS is positive

Step-by-step explanation

The spontaneity of a reaction can be determined by the sign of the Gibbs free energy change. For a spontaneous reaction, the change in Gibbs free energy should be negative, that is:

`\Delta G=\Delta H-T\Delta S`

The spontaneity of a process can depend on the temperature. Since the temperature value here corresponds to the absolute temperature, this implies that T > 0 for any T. Therefore, to have a negative difference for any temperature value, the change in enthalpy (ΔH), should be negative and the change in entropy (ΔS) should be positive so that we always subtract a positive number from a negative number. This corresponds to a negative value in ΔG.

Hence, the