I am confusing about the delta G(free-energy change). Could any one

In summary, free energy is the ability to do work and is affected by the sign of delta G. Endergonic reactions absorb free energy from the environment and have a positive delta G, while exergonic reactions release free energy and have a negative delta G. The relationship between delta G and delta S (entropy) is that the change in entropy alone does not influence delta G, but the change in enthalpy must also be taken into account.
  • #1
quynhchi0907
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I am confusing about the delta G(free-energy change). Could anyone explain me more about the sign of delta G. wat the exergonic and endergonic process mean? also, wat is the relation between the delta G and delta S(entropy)? I know the formula between them, but I don't quite understand

Thank you,
 
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Free energy is essentially the ability to do work. A reaction where free energy is absorbed from the environment has work being done on the reactants (this is endergonic, delta G is positive). When free energy is release by a reaction, the reactants have done work on the environment (this is exergonic, delta G is negative). The entropy of a system represents the amount of disorder when a reaction occurs. It will determine how much of the available energy in a system can do work. Change in entropy alone, however, does not influence delta G. The change in enthalpy (H) must also be known.
 
  • #3
for reaching out for clarification on the concept of delta G (free-energy change). Delta G is a measure of the thermodynamic potential of a system to do work. The sign of delta G indicates the direction of a spontaneous reaction, with negative values indicating an exergonic (energy-releasing) process and positive values indicating an endergonic (energy-consuming) process.

Exergonic processes occur spontaneously and release energy, while endergonic processes require energy input to occur. An example of an exergonic process is the breakdown of glucose during cellular respiration, which releases energy for the cell to use. An example of an endergonic process is the synthesis of glucose from smaller molecules, which requires energy input from the cell.

The relationship between delta G and delta S (entropy) is described by the equation delta G = delta H - T*delta S, where delta H is the change in enthalpy (heat energy) and T is the temperature in Kelvin. This equation shows that delta G is influenced by both the change in enthalpy and the change in entropy. A negative delta G value indicates that the reaction is spontaneous and that the system is becoming more ordered (decreasing in entropy), while a positive delta G value indicates a non-spontaneous reaction and an increase in disorder (increase in entropy).

I hope this explanation helps clarify your confusion about delta G and its relationship to delta S. If you have any further questions or need additional clarification, please don't hesitate to ask. As a scientist, it is important to fully understand these concepts in order to accurately interpret and analyze data related to thermodynamics and chemical reactions.
 

Related to I am confusing about the delta G(free-energy change). Could any one

What is delta G (free-energy change)?

Delta G, or free-energy change, is a measure of the amount of energy released or absorbed during a chemical reaction. It is a measure of the spontaneity of a reaction and can be used to predict whether a reaction will occur spontaneously or not.

How is delta G related to equilibrium?

At equilibrium, the value of delta G is equal to zero, meaning that there is no net change in the concentration of reactants and products. If delta G is negative, the reaction is spontaneous and will proceed towards equilibrium. If delta G is positive, the reaction is non-spontaneous and will not occur without an input of energy.

How does temperature affect delta G?

Increasing the temperature generally leads to a decrease in delta G for exothermic reactions and an increase in delta G for endothermic reactions. This is because temperature affects the enthalpy (heat) and entropy (disorder) components of delta G, which in turn influence the spontaneity of a reaction.

Can delta G be used to predict the direction of a reaction?

Yes, delta G can be used to predict the direction of a reaction. If delta G is negative, the reaction will proceed spontaneously in the forward direction. If delta G is positive, the reaction will not occur spontaneously and may require an input of energy to proceed in the reverse direction.

How is delta G calculated?

Delta G can be calculated using the equation delta G = delta H - Tdelta S, where delta H is the change in enthalpy, T is the temperature in Kelvin, and delta S is the change in entropy. The values of delta H and delta S can be determined experimentally or from standard values in tables.

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