Which statement is true about exergonic reactions?
a. in exergonic reactions, δg is positive due to the absorption of free energy.
b. exergonic reactions use more free energy than the amount of energy they produce.
c. exergonic reactions usually occur spontaneously because they require less energy of activation..

The answer is C. Exergonic reactions occur spontaneously (no outside energy is required to start them). It may be defined as a spontaneous reaction or a favorable reaction. Other characteristics of exergonic reactions include: 1.They release energy to the surroundings. 2. The free energy of the system decreases. 3. Change in entropy increases. Another way to look at it is that the disorder of the system tends to increase. Examples of an exergonic reaction would include exothermic reactions, such as mixing sodium and chlorine to make table salt.