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

Exam questions on The ideal gas equation and kinetic theory

1. 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
2. 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
3. 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