Explain real gases showing deviations from ideal gas with correction of pressure and volume and derive van der Waals equation.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) Real gases deviate from ideal behavior at high pressure and low temperature. The ideal gas equation $PV = nRT$ is based on two assumptions of the kinetic theory of gases which do not hold true for real gases:
$1.$ The volume occupied by gas molecules is negligible compared to the total volume of the gas.
$2.$ There are no forces of attraction between gas molecules.
Van der Waals introduced corrections for these:
Volume Correction: The effective volume available for the movement of molecules is $(V - nb)$,where $b$ is the excluded volume per mole.
Pressure Correction: The observed pressure $P$ is less than the ideal pressure due to intermolecular attraction. $P_{\text{ideal}} = P + \frac{an^2}{V^2}$,where $a$ is the attraction constant.
Substituting these into the ideal gas law $PV = nRT$,we get the van der Waals equation:
$(P + \frac{an^2}{V^2})(V - nb) = nRT$.

Explore More

Similar Questions

Van der Waals equation for a gas is stated as,
$p = \frac{nRT}{V - nb} - a\left( \frac{n}{V} \right)^2$
This equation reduces to the perfect gas equation,$p = \frac{nRT}{V}$,when:

The van der Waals equation is valid for $......$.

For a real gas (molar mass $= 60 \, g/mol$),if the density at the critical point is $0.80 \, g/cm^3$ and its critical temperature $T_c = \frac{4 \times 10^5}{821} \, K$,then the van der Waals constant $a$ (in $atm \, L^2 \, mol^{-2}$) is:

Difficult
View Solution

$A$ gas described by van der Waal's equation:

Which statement is correct regarding the equation $Z = PV/RT$?

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo