Questions & Answers

If \[\Delta G = \] negative for a reaction, then reaction is:
A. exergonic
B. endothermic
C. exothermic
D. endergonic

Answer Verified Verified
Hint: Exergonic reactions are favorable reactions. Endergonic reactions are unfavorable reactions. A negative ∆G also means that the products of the reaction have less free energy than the reactants because they gave off some free energy during the reaction. Reactions that have a negative ∆G have consequently, release free energy

Complete step by step answer:
A negative ∆G means that the reactants, or initial state, have more free energy than the products, or final state. Exergonic reactions are also called spontaneous reactions, because they can occur without the addition of energy. Reactions that have a negative ∆G release free energy and are called exergonic reactions.
An exergonic process is one in which there is a positive flow of energy from the system to the surroundings. This is in contrast with an endergonic process. Constant pressure, constant temperature reactions are exergonic if and only if the Gibbs free energy change is negative.
Favorable reactions have \[\Delta G\] values that are negative. They are also called exergonic reactions.

So, the correct answer is “Option A”.

Note: Knowledge of reactions and their relation with \[\Delta G\] is required to solve these types of questions. When using Gibbs free energy to determine the spontaneity of a process, we are only concerned with changes in delta G rather than its absolute value. Exergonic reactions can be coupled to endergonic reactions. Oxidation-reduction (redox) reactions are examples of the coupling of exergonic and endergonic reactions. Enzymes often act by coupling an endergonic reaction to the exergonic hydrolysis of ATP.