The ideal gas equationAQA A-Level Chemistry: Mind map

Exam questions on The ideal gas equation

1. A sample of nitrogen gas is held in a rigid flask of volume 250 cm³. The gas is at a temperature of 27 °C and a pressure of 120 kPa.
   Calculate the amount, in mol, of nitrogen in the flask. The gas constant, R = 8.31 J K⁻¹ mol⁻¹.2 marks
2. A sealed, rigid steel cylinder of fixed volume contains helium used to fill party balloons. The cylinder is stored in a warehouse where the temperature changes between night and day.
   Use the ideal gas equation to explain why the pressure in the cylinder is higher on a hot day than at night.2 marks
3. A student determines the relative molecular mass of a volatile liquid. She injects 0.223 g of the liquid into a gas syringe held in an oven at 100 °C. The liquid vaporises completely and the vapour occupies 95.0 cm³ at a pressure of 101 kPa. The gas constant, R = 8.31 J K⁻¹ mol⁻¹.
   Calculate the amount, in mol, of vapour in the gas syringe.3 marks