A level: Kinetic Theory Questions

Q5.

(a) The volume of air in a fully expanded pair of human lungs is 5.0 × 10^–3 m³.

The pressure of the air in the lungs is 1.0 × 10⁵ Pa and its temperature is 310 K.

Calculate:

(i) the number of moles of air in the lungs,

(ii) the average kinetic energy of an air molecule in the lungs.

(4 marks)

(b) Air is a mixture of oxygen and nitrogen molecules.

The mass of an oxygen molecule is greater than the mass of a nitrogen molecule.

State and explain the effect this has on the mean square speeds of the oxygen and nitrogen molecules in the lungs.

(3 marks)

(Total 7 marks)