Difference between the two following formulas

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Discussion Overview

The discussion revolves around the differences between two thermodynamic formulas: dQ = dU + dW and dU = dQ + dW. Participants seek clarification on the contexts in which each formula is used and the implications of the conventions involved.

Discussion Character

  • Conceptual clarification

Main Points Raised

  • Some participants inquire about the differences between the two formulas and their applications.
  • One participant suggests that the question may relate to different conventions used by physicists and chemists regarding the first law of thermodynamics.
  • Another participant clarifies that in the first equation, dW represents the work done by the system on the surroundings, while in the second equation, dW represents the work done by the surroundings on the system, noting that both conventions are used depending on the author.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the use of the formulas, as different conventions are acknowledged without resolution of which is preferable.

Contextual Notes

The discussion highlights the dependence on conventions and the potential for confusion arising from different interpretations of work in thermodynamic equations.

Kibz665
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Can some one please tell me what is the difference between the two following formulas and when it is used:
dQ=dU+dW
dU=dQ+dW
 
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Are you asking about the different conventions used by physicists and chemists for the 1st law..?
 
Kibz665 said:
Can some one please tell me what is the difference between the two following formulas and when it is used:
dQ=dU+dW
dU=dQ+dW
In the first equation, dW represents the work done by the system on the surroundings. In the second equation, dW represents the work done by the surroundings on the system. Both conventions are used, depending on the author.
 
Thanks that was very helpful.
 

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