Chemical Forums
Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: John_Astley on May 19, 2013, 09:54:24 AM
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Hi everyone. I have this problem that I can't seem to get through. I would greatly appreciate it if anyone could help or point me out in the right direction. Here's the problem:
"Consider the three following mixtures:
1) acetone and chloroform
2) n-hexane and n-heptane
3) acetone and benzene
-Which of these shows ideal behavior, which shows positive deviation from Raoult's law and which shows negative deviation from Raoult's law?
-Which of these, individually, has a value of delta H of mixing that is equal to zero, greater than zero and smaller than zero?
-Which of these, individually, has a value of delta V of mixing that is equal to zero, greater than zero and smaller than zero?
-Explain all of your answers according to molecular interactions."
I have no clue where to start. Any help would be greatly appreciated. Thank you in advance.
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Start by explaining what Raoult's Law is, and under what circumstances there is positive or negative deviation. This is something you can easily look up in a textbook.
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I can determine these problems given the vapor pressure and moles of each component in each mixture but I'm not given any of that here, that's why I'm confused. How could I go about doing so then?
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Not every problem in chemistry is about dealing with numerical values. Which is why I suggest starting with a definition of what Raoult's Law says, and under what circumstances you will have deviations from it. You may also want to look up what an Ideal Gas is, and learn about why some gasses do not have ideal behavior.
Do a little research on those topics and if you still have specific questions about them, let us know.
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I figured it out. Thanks.