Questions tagged [van-der-waals-behavior]

Questions with substantial discussion on the behavior of real gases using the van der Waals model (as opposed to just calculations with the van der Waals equation, or a casual reference to the van der Waals model).

7 questions with no upvoted or accepted answers
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About Real Gas and Ideal Gas - Select the correct statement(s):

Select the correct statement(s): At Boyle's temperature a real gas behaves like an ideal gas at low pressure. Above critical conditions, a real gas behaves like an ideal gas. At high pressure van der ...
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147 views

Why is it experimentally difficult to accurately find the critical volume of a real gas?

I was reading up on the derivation of the values of various critical state functions( $\ce{Vc}$, $\ce{pc}$ and $\ce{Tc}$) from the Van der Waals equation (Physical Chemistry by G.W. Castellan). There, ...
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Student Question regarding molecular van der Waals volume and Polarizability

I would like to request a crosscheck of my understandings regarding molecular van der Waals volume and polarizability. Please have a look through my statements about these 2 concepts below and point ...
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107 views

Is a/b > 1 mol/L for a and b in the van der Waals equation?

We know that the van der Waals equation for real gases is $$\left(p + \frac{an^2}{V^2}\right)(V-nb) = nRT.$$ Is $a > b$ always in this equation? In my textbook $a > b$ for gases like $\ce{He},$ $...
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Are spontaneous/induced dipoles the same as van der Waals forces?

I am puzzled by the names of dipoles. What is the difference among permanent dipoles, spontaneous dipoles, van der Waals forces, and intermolecular forces? Does "The intermolecular force" ...
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When do repulsive forces in a gas actually become dominant?

We say that repulsive forces become dominant when Z>1 (i.e. Vobserved > Vtheoretical). But when the difference between Vobserved and Vtheoretical is less than b, shouldn't attractive forces ...
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529 views

What is the value of isothermal compressibility of a van der Waals gas at critical point?

For a van der Waals gas, isothermal compressibility is $$\kappa=\frac{V^2(V-nb)^2}{nRTV^3-2an^2(V-nb)^2}$$ If one substitutes the values of critical temperature and volume in this formula, isothermal ...