Question

Spontaneous Reactions are:
A. Endergonic
B. Exergonic
C. Energy neutral
D. Exer-endergonic reactions

Answer 1

Hint: A spontaneous reaction supports the formation of products at the conditions under which the reaction is occurring. Spontaneous reaction supports decrease in energy and an increase in entropy which means that combustion reactions occur spontaneously. it is exothermic (decrease in the energy of the system as energy is released to heat the surrounding ). We can take an example of combustion reaction .The products of a fire are composed partly of gases such as carbon dioxide and water vapor. The entropy of the system increases during a combustion reaction. The combination of energy decrease and entropy increase which means combustion reactions are spontaneous reactions.

Complete step by step solution:

We know about the Gibbs free energy $\Delta G$ which is a thermodynamic potential that is used to calculate the maximum of reversible work performed by a thermodynamic system at a constant temperature and pressure. Exergonic reactions have a negative $\Delta G$ release free energy. Exergonic means energy is Exiting the system. A negative $\Delta G$ means that the reactants, or initial state, have more free energy than the products, or final state. So Exergonic reactions are also spontaneous reactions, because they can occur without the addition of energy.Endergonic reactions positive $\Delta G$ ($\Delta G > 0$), these reactions require an input of energy. In this case, the products, or final state, have more free energy than the reactants, or initial state. Endergonic reactions are nonspontaneous, meaning energy must be added before they can proceed. We can understand about endergonic reactions as storing some of the added energy in the higher-energy products .
So spontaneous reactions are exergonic reactions.

Note: We have solved this problem by recalling the concepts of the Gibbs free energy $\Delta G$. Positive and negative values of $\Delta G$ shows the type of reaction that is either exergonic reactions or endergonic reactions.