Van der Waals Equation

IMPORTANT

Van der Waals Equation: Overview

This topic covers concepts such as Compressibility Factor, Variation of Compressibility Factor with Temperature, Variation of Compressibility Factor with Pressure, van der Waals Equation for Real Gases, Units of van der Waals Constants, etc.

Important Questions on Van der Waals Equation

EASY
IMPORTANT

In Van der Waal’s equation of state for a non-ideal gas, the term that accounts for intermolecular forces is:

MEDIUM
IMPORTANT

Van der Waal’s real gas, act as an ideal gas, at which conditions ?

EASY
IMPORTANT

At which one of the following temperature – pressure conditions the deviation of a gas from ideal behaviour is expected to be minimum ?

EASY
IMPORTANT

When deviation is more in the behaviour of a gas from the ideal gas equation PV = nRT ?

MEDIUM
IMPORTANT

Significance of Van der Waals Constant 'b'

EASY
IMPORTANT

According to kinetic theory, the gas particles occupy a negligible fraction of the total volume of the gas. This assumption is responsible for the volume correction in the ideal gas equation of real gases.

EASY
IMPORTANT

Mentions two assumptions of kinetic theory of gases, which are responsible for the volume correction in the ideal gas equation of real gases.

MEDIUM
IMPORTANT

Explain the factors responsible for the volume correction in the ideal gas equation of real gases.

EASY
IMPORTANT

Which of the following expressions is correct between the van der Waals constant b and the radius r of spherical molecules?

EASY
IMPORTANT

For an ideal gas, the compressibility factor is

HARD
IMPORTANT

For one mole of a van der Waals' gas, the compressibility factor Z=pVRT at a fixed volume will certainly decrease, if
[Given : " a " and " b " are standard parameters for van der Waals' gas]
 

EASY
IMPORTANT

n2av2 is also called internal _____ of the gas where 'a' is a measure of force of attraction between gas molecule.

EASY
IMPORTANT

Which of the following represents a plot of compressibility factor Z vs pressure P at room temperature for O2?

HARD
IMPORTANT

For one mole of a van der Waals gas when b=0 and T=300 K, the PV vs I/V plot is shown below. The value of the van der Waals constant 'a' (atm. litre2 mol-2) is
Question Image

HARD
IMPORTANT

For 1 mole of gas II, the van der Waals equation reduces to the form

HARD
IMPORTANT

In fig. (b), the correct order of temperatures is

HARD
IMPORTANT

In fig. (a), the gas which is above the Boyle temperature is

HARD
IMPORTANT

If Vo is the observed volume of a gas and Vi is the ideal gas or volume, then the compressibility factor (Z) for the gas is

EASY
IMPORTANT

Select the correct order followed by boyle's temperature (Tb), critical temperature Tc, and inversion temperature Ti .

MEDIUM
IMPORTANT

Using van der Waal's equation, calculate the constant 'a' when two moles of gas confined in a four litre flask exert a pressure of 11.0 atm at a temperature of  300 K . The value of 'b' is 0.05 L  mol -1 .