What is the molecular picture of a low-density gas?

Its molecules are widely spaced, move rapidly and randomly, and interact appreciably mainly during collisions.

What is the molar ideal gas law?

For an ideal gas, $pV=nRT$, where $n$ is amount in moles and $R$ is the gas constant.

How are molecule count and amount in moles related?

$N=N_A n$, where $N_A$ is Avogadro’s number.

What do the van der Waals constants $a$ and $b$ correct for?

$a$ accounts for intermolecular attractions; $b$ accounts for the finite volume occupied by molecules.

What is a supercritical fluid?

A substance above its critical point, with no distinct liquid–gas boundary.

ThermodynamicsLesson 1 of 1 in the course The Kinetic Theory of Gases

Ideal-Gas Laws, Real-Gas Corrections, and Phase Behavior

5 flashcards · 5 quiz questions · 5 match pairs · 5 fill-in sentences · English

Save course

Lesson progress

0 / 5

Your progress is kept in this browser only.Sign up to save it

Summary

This lesson explains how the microscopic structure of a gas helps account for its macroscopic behavior, and introduces the experimental gas laws.

Gas molecules are typically far apart compared with their own size. Under ordinary conditions, the forces between them are therefore small except during collisions. Molecules move rapidly and randomly, collide with one another and with container walls, and spread to fill all accessible space.

All flashcards

What is the molecular picture of a low-density gas?: Its molecules are widely spaced, move rapidly and randomly, and interact appreciably mainly during collisions.
What is the molar ideal gas law?: For an ideal gas, $pV=nRT$ , where $n$ is amount in moles and $R$ is the gas constant.
How are molecule count and amount in moles related?: $N=N_A n$ , where $N_A$ is Avogadro’s number.
What do the van der Waals constants $a$ and $b$ correct for?: $a$ accounts for intermolecular attractions; $b$ accounts for the finite volume occupied by molecules.
What is a supercritical fluid?: A substance above its critical point, with no distinct liquid–gas boundary.

Quiz questions

For a sealed sample of ideal gas moving between two equilibrium states, which relation applies?Answer: $\frac{p_1V_1}{T_1}=\frac{p_2V_2}{T_2}$
How is the average molar mass of a gas mixture calculated from its components?Answer: By weighting each component’s molar mass by its fraction in the mixture.
In the van der Waals equation, what does $V-nb$ represent?Answer: The volume available for molecular motion after accounting for molecular size.
What is the shape of an ideal-gas isotherm on a pressure–volume diagram?Answer: A hyperbola, because pressure times volume is constant.
What happens above a substance’s critical temperature when pressure is increased?Answer: Pressure alone cannot produce an ordinary distinct liquid phase.

Based on University Physics Volume 2 by Samuel J. Ling, William Moebs, Jeff Sanny (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.

All Thermodynamics lessons

ThermodynamicsThermodynamic Systems, Equilibrium, and State Variables5 flashcards · 5 quiz questions · 4 gamesPlay free →ThermodynamicsAdiabatic Ideal-Gas Processes: Energy Changes and Quasi-Static Relations5 flashcards · 5 quiz questions · 4 gamesPlay free →

Summary

All flashcards

Quiz questions

More in Thermodynamics