Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: Entropy and states of matter



If your students have been taught that entropy is a
measure of disorder, they are unlikely to see any
"overcompensating increase in disorder" accompanying condensation.
However, if you take the time to make the proper connections
between entropy, internal energy, and heat, things ought to go
more smoothly.

John, here is another example where an unhelpful view of "heat" distracts
from good pedagogy. If one talks about "heat escaping" from the
condensate, it just confuses students. Wouldn't it be more helpful to say
it correctly? As the gas condenses negative work is done on the molecules
and hence their energy level decreases and so does the entropy of the
condensate. In the process positive work is done on the ambient gas and
hence it's energy level increases and so does the entropy. If one takes
the time to make the proper connection between entropy, internal energy,
and _work_, things ought to go more smoothly.

Jim Green
mailto:JMGreen@sisna.com
http://users.sisna.com/jmgreen