The ideal gas equation and kinetic theoryEdexcel International A Level Physics: Flashcards

What these 12 flashcards ask

State the ideal gas equation using N.
What is the value of the Boltzmann constant?
What units must be used in pV = NkT?
State Boyle's law.
Which graph should be straight for Boyle's law?
How do you keep temperature constant in the Boyle's law experiment?
What happens to p if T doubles at constant V and N?
What equation gives the mean kinetic energy of a molecule?
Which two equations do you combine to derive ½m⟨c²⟩ = (3/2)kT?
What is the root mean square speed?
Do lighter or heavier molecules have a higher crms at the same T?
How does mean kinetic energy change when the kelvin temperature doubles?

Exam questions on The ideal gas equation and kinetic theory

A sealed flask of volume 2.0 × 10⁻³ m³ contains an ideal gas at a pressure of 1.0 × 10⁵ Pa and a temperature of 300 K. The Boltzmann constant is k = 1.38 × 10⁻²³ J K⁻¹.
Calculate the mean kinetic energy of a molecule of the gas.2 marks
A class investigates the relationship between the pressure and volume of a fixed mass of air at constant temperature. The air is trapped in a syringe connected to a pressure gauge, and the students change the volume with the plunger and record the pressure each time.
The air is at a pressure of 1.00 × 10⁵ Pa when its volume is 60 cm³. The students compress it to 24 cm³ at constant temperature. Calculate the new pressure.2 marks
Helium is used to fill a weather balloon. A helium atom has mass 6.64 × 10⁻²⁷ kg. The gas can be treated as ideal and is at a temperature of 300 K. The Boltzmann constant is k = 1.38 × 10⁻²³ J K⁻¹. Argon atoms have a mass of 6.63 × 10⁻²⁶ kg.
Calculate the root mean square speed of the helium atoms.3 marks

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).