Process such as isobaric, isochoric, quasistatic, adiabatic

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Discussion Overview

The discussion revolves around thermodynamic processes such as isobaric, isochoric, quasistatic, and adiabatic, specifically focusing on the conservation of entropy and the calculation of enthalpy in these contexts. Participants explore the conditions under which entropy may be conserved and the implications for ideal gases.

Discussion Character

  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions whether there are special cases where entropy is conserved in processes involving ideal gases, suggesting a potential confusion with enthalpy.
  • Another participant states that total entropy is conserved in reversible processes and that system entropy is conserved in reversible processes without heat flow.
  • A participant inquires about the applicability of the equation ΔH = nCpΔT when pressure is not constant, indicating uncertainty about its general use.
  • Further clarification is provided on the concept of reversible processes, describing them as idealizations where no gradients exist in temperature or pressure, and noting that such conditions are not realizable in real life.

Areas of Agreement / Disagreement

Participants express differing levels of understanding regarding reversible processes and the conditions for entropy conservation, indicating that multiple competing views remain and the discussion is not resolved.

Contextual Notes

There are limitations in the discussion regarding the definitions of reversible processes and the assumptions underlying the conservation of entropy and enthalpy calculations, which remain unresolved.

cos(e)
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Just say an ideal gas goes through process such as isobaric, isochoric, quasistatic, adiabatic etc, is there any special cases where entropy is conserved, or am i thinking enthalpy. Also how is enthalpy found in adiabatic processes?
 
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Total entropy is conserved in reversible processes. System entropy is conserved in reversible processes without heat flow (reversible work doesn't carry entropy).

For an ideal gas, enthalpy H is nc_PT+H_0, so for any process \Delta H=nc_P\Delta T.
 


do we use delta H= n*Cp* delta T even when the pressure is not constant?

What do u mean by reversible process, i havnt learned that yet :S
 


cos(e) said:
do we use delta H= n*Cp* delta T even when the pressure is not constant?

For an ideal gas; it's a special case.

cos(e) said:
What do u mean by reversible process, i havnt learned that yet :S

A reversible process is an idealization in which no gradients exist in temperature, pressure, or any intensive properties. It's not realizable in real life, where the only way to transfer energy is by differences in temperature, pressure, etc. But if we assume the differences are small enough to be negligible, it makes the calculations easier precisely because we can assume that entropy generation is zero. More http://en.wikipedia.org/wiki/Reversible_process_(thermodynamics)" .
 
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