Martian Climate. The atmosphere of Mars is mostly CO2 (molar mass 44.0 g/mol) under a pressure of 650 Pa, which we shall assume remains constant. In many places the temperature varies from 0.0o C in summer to – 100o C in winter. Over the course of a Martian year, what are the ranges of (a) the rms speeds of the CO2 molecules and (b) the density (in mol/m3) of the atmosphere?
Solution 36E Step 1: The root mean square velocity is given by Vrms= 3RT/M 3 Here M molecular mass of gas(M = 44 × 10 kg/mol) T temperature of gas(273 K) R universal gas constant(R = 8.314 J/mol.K) Change the temperature for degree celsius to kelvin 0 1 C = 273 K Step 2: (a). V rms= 3RT/M V rms= 3(8.314 J/mol.K)(273 K)/(44 × 103kg/mol) V = 393 m/s rms