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Here are some questions that a student who has been studying thermodynamics should be able to answer:
- How would you explain the difference between phase equilibrium and a phase transition to a student in general chemistry? Better yet, if you were a student in physical chemistry, who had just worked through some activities on vapor pressure and single component phase diagrams, how would you explain the difference to another student in the class?
- Why don’t equilibrium constants have units?
It has been quite a while since I’ve posted anything, and I apologize to all the tens of readers I have out there. I admit, I’ve been somewhat lazy, but I’ve tried to make sure that everything else I have to do got done. I guess this blog is lower priority.
We have been hitting a variety of topics in class, from chemical equilibrium to phase equilibrium, and a few places in between. What do they all have to do with one another? Quite simply, ΔG. And the good news is, that won’t go away for a while!
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Nanotechnology is booming. New applications are popping up everywhere, from cancer drug delivery, to solar cells. My favorite part of nanotech is its wide applicability, which is increasingly leading to interdisciplinary research – biologists working with chemists, chemists working with physicists… You get the picture. When the artificial barriers between disciplines come down, all you have is the process of doing science, and you find that what we really have in common is curiosity.
If you’re interested in learning more about nanotechnology, try this link to Northwestern University’s DiscoverNano website. There is nano research going on at Linfield, both in my research group, and in Dr. Crosser’s (Physics), so if you want to get your hands dirty (well, not literally, I hope) you should talk to us.
I think this video should be required viewing for anyone who is even remotely interested in science. Take the time to watch it, and then let me know what you think. You can see more like this at the Charlie Rose website.
Poor equilibrium constants, without their units! Why are they unitless? It’s actually pretty simple, but most of the time general chemistry textbooks hide the truth from you. But you can handle the truth, right? Ok, here it is.
So, now you know what the title of this blog really is! We’ve developed an array of different quantities that tell us if a process will occur irreversibly (i.e., the final state can’t get back to the initial state following the same pathway). I don’t really like it, but this is the definition of spontaneous. I’d much rather just leave it irreversible, but I’m fighting history here.
The three quantities we have are ΔS total, ΔG (the change in the Gibbs free energy), and ΔA (the change in the Helmholz free energy).
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