Given the following information Mw N2 = 28.01, O2 = 32, R= 8.314 kPa.L/mol.K and 1bar=100kPa:
(a) Calculate the molar mass of the earth's atmosphere at an altitude of 500 km where the pressure is 1.6 x 10-11 bar, the temperature is, on average, 1580K and the density is 2.2 x 10-12 g/L
(b) Using the answer you obtained in part (a) calculate the composition of the earth's atmosphere at 500km. Assume that it consists only of nitrogen molecules and oxygen (O) atoms (i.e. not O2 molecules).
(c) In this example you are assuming ideal gas behaviour. Why can you not always assume a gas is ideal?