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Need an example of decrease in entropy caused by heat input

TheInquisitor

New Member
Yeah that's a good example. I also considered formation of crystals like diamond under intense heat and pressure, but I don't understand thermodynamics well enough to know if these are examples of an increase or decrease in entropy.
 

aeroeng314

Member
Doesn't pooping decrease our entropy? I always figured waste products were a way of transporting entropy out of the system.
 
Homunclus said:
What about chemical reactions like the production of ammonia that require great quantities of heat and pressure:

N2(g) + 3H2(g) ⇌ 2NH3(g)

The usage of heat as a means of creating more complex substances from simpler ones seems like an "intuitive increase of complexity"

Actually, the formation of ammonia has negative enthalpy, it's exothermic, so in order to move the equilibrium towards higher levels of ammonia, you need lower temperatures. (So the equilibrium does more of the forward reaction to heat up the mixture (Le Chatelier's Principle))
However, lower temperatures mean a much slower reaction, so there has to be a compromise between yield and rate.
If you could get 100 bottles in 2 months, or 10 bottles in an hour, you'd pick the former because overall you get more.
 
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