Question

A gas described by van der Waal's equation

• A. behaves similar to an ideal gas in the limit of large molar volumes
• B. behaves similar to an ideal gas in the limit of large pressures
• C. is characterized by van der Waal's coefficients that are dependent on the identify of the gas but are independent of the temperature
• D. has the pressure that is lower than the pressure exerted by the same gas behaving ideally

Answer 1

Answer: (A), (C), (D)

$\left(P+\frac{n^{2}a}{V^2}\right)(V-nb)=nRT$
At low pressure, when the sample occupies a large volume, the molecules are so far apart for most of the time that the intermolecular forces play no significant role, and the gas behaves virtually perfectly.
$a$ and $b$ are characteristic of a gas and are independent of temperature.
The term $\left(P+\frac{n^{2}a}{V^2}\right)$ represents the pressure exerted by an ideal gas while $P$ represents the pressure exerted by a real gas.