Free Energy Change (ΔG) and Reaction Direction Prediction

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According to the first law of thermodynamics, what is true about the total energy of a system?

The total energy of a system, including its surroundings, remains constant. (correct)

The total energy of a system can be created or destroyed during a change.

The total energy of a system is constantly decreasing.

The total energy of a system is constantly increasing.

What does the second law of thermodynamics state about the entropy of a system?

The entropy of a system has no bearing on whether a process will occur spontaneously.

The entropy of a system must always remain constant for a process to occur spontaneously.

The entropy of a system must always decrease for a process to occur spontaneously.

The entropy of a system must always increase for a process to occur spontaneously. (correct)

Which of the following best describes the relationship between Gibbs free energy change (ΔG) and the changes in enthalpy (ΔH) and entropy (ΔS) during a chemical reaction?

ΔG = ΔH + TΔS

ΔG = ΔH - TΔS (correct)

ΔG = ΔH * TΔS

ΔG = ΔH / TΔS

Which of the following statements about the Gibbs free energy change (ΔG) is correct?

A negative ΔG indicates that the reaction is spontaneous and releases energy. Signup and view all the answers

Which of the following statements about the relationship between ΔG, ΔH, and ΔS is correct?

A reaction with a negative ΔH and positive ΔS will have a negative ΔG. Signup and view all the answers

Which of the following statements about the relationship between Gibbs free energy (G) and the spontaneity of a reaction is correct?

A reaction with a negative ΔG is spontaneous, while a reaction with a positive ΔG is non-spontaneous. Signup and view all the answers

What does a negative ΔG value indicate about a reaction?

The reaction goes spontaneously from A to B Signup and view all the answers

In which scenario is ΔG zero?

The system is at equilibrium Signup and view all the answers

What happens if ΔG is a positive number?

The reaction requires energy to proceed from B to A Signup and view all the answers

What is the significance of ΔG°′ in biochemistry?

It defines the pH of the standard state Signup and view all the answers

What does it mean when ΔG has a great magnitude in a reaction?

The reaction goes virtually to completion and is essentially irreversible Signup and view all the answers

How does ΔG allow prediction of the direction of a reaction?

By indicating whether the reaction goes spontaneously or requires energy input Signup and view all the answers

What is the relationship between the Gibbs free energy change (ΔG) and the standard free-energy change (ΔG°) for a chemical reaction?

ΔG = ΔG° - RT ln([B]/[A]) Signup and view all the answers

What is the significance of the standard free-energy change (ΔG°) in chemical reactions?

All of the above. Signup and view all the answers

How is the equilibrium constant (K'eq) related to the standard free-energy change (ΔG°')?

ΔG°' = -RT ln K'eq Signup and view all the answers

What is the difference between exergonic and endergonic processes in biological systems?

Exergonic processes release free energy, while endergonic processes require free energy. Signup and view all the answers

What is the significance of coupling in biological systems?

Coupling allows endergonic processes to proceed by linking them to exergonic processes. Signup and view all the answers

Which statement about the laws of thermodynamics is correct?

The first law of thermodynamics states that energy is conserved in a closed system. Signup and view all the answers