(adsbygoogle = window.adsbygoogle || []).push({}); Calculate "a" values given equation of state for gases

1. The problem statement, all variables and given/known data

For my equation of state:

V_{m}= (RT/P) - (a/T)

what kind of sign for the constant a (positive or

negative) do you think the following gases will have and why:

a. H2 b. He c. CH4 d. CO2

Hint: There isalmostno math involved.

2. Relevant equations

V_{m}= (RT/P) - (a/T) (obviously, lol)

I'm thinking critical values also might play a role, but since my professor stated that nearly no math is involved, I'm thinking that the answers are mostly derived from the given equation.

3. The attempt at a solution

Honestly I have no idea where to start with this. I know in the standard Van der Waal's equation that the a values represent the error intermolecular attractions, and that the values for hydrogen and helium are very small because they basically have no attraction. I'm guessing negative values would represent intermolecular repulsion...any help is appreciated

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# Homework Help: Calculate a values given equation of state for gases

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