Don't understand van der Waals equation?
I seriously don't understand van der Waals equation. My book doesn't explain it at all.
I'm trying to answer this question:
"Without looking at the table of values, which of the following gases would you expect to have the largest value of the van der Waals constant b: H2, N2, CH4, C2H6, or C3H8?"
If you know how to answer that, what the difference between constant "a" and "b" is, and how to explain what van der Waals equation is, then your help is much appreciated.
Thanks in advance.
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Van der Waals equation is an attempt to modify the ideal gas equation PV=nRT to take into account two factors that are different from the definition of an ideal gas.
1) There is some interaction between molecules so they will exert less pressure on the container
2) The molecules do take up some volume.
We therefore get (P + a/V^2) to alter the pressure and (v-b) to reduce the total volume
Thus a large molecule will have a high value of 'b' as it takes up more space.
A large molecule will also have more interaction between it and other molecules (Van der Waals forces increase with molecular size generally)
Thus Propane should have the largest 'b' value
(If interested: for propane a= 8.779 and b = 0.08445 and toluene (for comparison a much bigger molecule) 24.38 0.1463 respectively
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Don't understand van der Waals equation?
I seriously don't understand van der Waals equation. My book doesn't explain it at all.
I'm trying to answer this question:
"Without looking at the table of values, which of the following gases would you expect to have the largest value of the van der Waals constant b: H2,...