1. The problem statement, all variables and given/known data Consider a mixture of oxygen and hydrogen kept at room temperature.As compared to a hydrogen molecule an oxygen molecule hits the wall- (a) with greater average speed (b)with smaller average speed (c)with greater average kinetic energy (d)with smaller average kinetic energy 2. Relevant equations We have to consider both the gases as ideal to get the answer. Now, for a mixture vrms=(3RT/M)^1/2 where M is average mass of the gases in the mixture and is M=(n1M1+n2M2)/n1+n2 n denote the number of moles of gases and M their respective molecular masses. Average kinetic energy for a gas molecule=3/2kT k=boltzmann constant T=absolute temperature 3. The attempt at a solution The answer given is (b)with smaller average speed.Someone please explain the reason for this.