Question

From the choices below, the change in free energy for the reaction that is exergonic will probably be zero 0 -2.1 O + 2.1 it varies between +2.1 and -2.1

Answer 1

Answer) -2.1

The correct answer will be -2.1 because exergonic reactions are spontaneous reactions, so that the change in free energy in these chemical reactions will be always negative. These reactions will release their free energy into the surrounding easily, so it is termed as spontaneous reactions. They will not consume the energy. Because of this process the free energy of the system will be decreased and as a result of this the Gibbs free energy(G) will also be termed as negative.

That is, $\Delta$ G = $\Delta$ H-T$\Delta$S

$\Delta$G = Gibbs free energy

$\Delta$H = Enthalpy

T= Temperature

$\Delta$S = Entropy of the system

For an exergonic reaction, the free energy is released therefore the $\Delta$ G value becomes negative and such that the reaction will be spontaneous. The entropy of an exergonic system will always increases. Free energy of the system is the total amount of energy that is available on the system. The examples for exergonic reactions are cellular respiration,glycolysis,combustion,chemiluminescence. In all these reactions the energy is released out of the system, for example in chemiluminescence light energy is released out of the system.

The other options zero,+2.1, it varies from +2.1 to -2.1 is incorrect for the reason that $\Delta$ G< 0 ,so that zero cannot be the answer. Considering +2.1, it is a positive value so that it cannot indicate an exergonic reaction. The next varies from a positive value to a negative value, so that it is not the correct option.