Which, if any, is/are valid forms of the Second Law of Thermodynamics?

AI Thread Summary
The discussion centers on the validity of various statements regarding the Second Law of Thermodynamics. Several statements were affirmed as true, including the impossibility of creating a perpetual motion machine that extracts heat without work and the natural tendency for entropy to increase. However, two statements were identified as false: the equation "Ein - Ein = ∆Esystem" and the claim that "Sgen ≤ 0" for all naturally occurring processes. The participant believes the confusion arises from the interpretation of the statement about transferring heat from a higher-temperature reservoir to a lower-temperature reservoir. Clarification on these points is sought to resolve the misunderstandings.
ss883
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What I answered is in brackets...what did I answer incorrectly?

  • It is impossible to construct a device that, operating in a cycle, will produce no effect other than the extraction of heat from a reservoir and the performance of an equivalent amount of work. [True]
  • For all naturally occurring processes, Sgen > 0. [True]
  • It is impossible to construct a device that, operating in a cycle, will produce no effect other than the transfer of heat from a lower-temperature reservoir to a higher-temperature reservoir. [True]
  • It is impossible to construct a device that, operating in a cycle, will produce no effect other than the transfer of heat from a higher-temperature reservoir to a lower-temperature reservoir. [True]
  • Ein - Ein = ∆Esystem [False]
  • For all naturally occurring processes, Sgen ≤ 0. [False]
  • All of the above statements are true. [False]
 
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ss883 said:
What I answered is in brackets...what did I answer incorrectly?

  • It is impossible to construct a device that, operating in a cycle, will produce no effect other than the extraction of heat from a reservoir and the performance of an equivalent amount of work. [True]
  • For all naturally occurring processes, Sgen > 0. [True]
  • It is impossible to construct a device that, operating in a cycle, will produce no effect other than the transfer of heat from a lower-temperature reservoir to a higher-temperature reservoir. [True]
  • It is impossible to construct a device that, operating in a cycle, will produce no effect other than the transfer of heat from a higher-temperature reservoir to a lower-temperature reservoir. [True]
  • Ein - Ein = ∆Esystem [False]
  • For all naturally occurring processes, Sgen ≤ 0. [False]
  • All of the above statements are true. [False]
[*] It is impossible to construct a device that, operating in a cycle, will produce no effect other than the transfer of heat from a higher-temperature reservoir to a lower-temperature reservoir. [True]

I think this one is the problem.
 
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