Understanding Free Gibbs Energy: The Role of TΔS in Thermodynamics

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SUMMARY

The discussion centers on the interpretation of TΔS in the context of the Gibbs free energy equation. Participants clarify that while TΔS can represent energy associated with entropy changes, it is often described as energy unavailable for work due to its dispersive nature. The example provided illustrates that in an exothermic reaction where ΔH is negative and ΔS is positive, the total energy change can still yield useful work, challenging the conventional view of TΔS. This highlights the complexity of thermodynamic systems and the need for precise definitions in thermodynamic literature.

PREREQUISITES
  • Understanding of Gibbs free energy and its equation
  • Knowledge of thermodynamic concepts such as enthalpy (ΔH) and entropy (ΔS)
  • Familiarity with exothermic and endothermic reactions
  • Basic principles of thermodynamics and energy transfer
NEXT STEPS
  • Research the implications of TΔS in different thermodynamic processes
  • Study the relationship between entropy and energy in thermodynamic systems
  • Explore the concept of free energy in non-equilibrium thermodynamics
  • Examine case studies of exothermic reactions and their energy profiles
USEFUL FOR

Students of chemistry and physics, thermodynamics researchers, and professionals involved in energy systems will benefit from this discussion.

david22
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I´m having serious problems with free gibbs energy equation. My main problem is that i don't know the meaning of TΔS that appears in free gibbs formula. I know that S is entropy and T temperature; but some books say that TΔS is energy lost or dispersal energy; energy unavailable to do work; but for example, let's say that the sistem loses 30 joules of heat so ΔH will be negative because it is an exothermic reaction; and let's say that the ΔS is positive at T=25°ℂ and let's say that TΔS = 30 joules. So if we add this numers in the equation -30J - 30J = -60J so this number is the energy useful to do work so this means that TΔS is also energy that is useful to do work, so my question is why some books say that this is energy unable to do work? and if you can give me a physical interpretation of TΔS ( what kind of energy is it?) i would appreciate it
 
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Hi David, welcome to PF!

Could you please provide quotes for the statement? Just saying "some books say that" is not very helpful (sometimes, conetxt is everything).

If \Delta S is positive, it usually means that heat is entering the system from the environment, which can indeed be used for additional work.
 

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