States of Matter 1 Question 34

34. In van der Waals’ equation of state for a non-ideal gas, the term that accounts for intermolecular forces is

(1988, 1M)

(a) $(V-b)$

(b) $R T$

(c) $\left(p+\frac{a}{V^{2}}\right)$

(d) $(R T)^{-1}$

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Solution:

  1. In van der Waals’ equation of state

$$ \left(p+\frac{a}{V^{2}}\right)(V-b)=R T $$

(For 1 mole)

The first factor $\left(p+a / V^{2}\right)$ correct for intermolecular force while the second term $(V-b)$ correct for molecular volume.