1. In combustion studies, air is assumed to be composed of 21% Oxygen molecule and 79% Nitrogen molecule by volume. Show that these volume fractions mean that for every mole of Oxygen molecule there exist 3.76 moles of Nitrogen molecule. 2. Consider a gas mixture of n species. Assume that i is an intensive property of species i, e.g., specific enthalpy. Prove that the mole-based specific value of the property, i.e., i can be obtained from: i=iMWi, where MWi is the molecular weight of the ith species. Also show that for the mixture: mix=i=1niiMWi=i=1nYi/MWii=1nYii, where Yi is the mass fraction of the ith species. For which intensive property, Eq. (1) results into the formulation for the mixture molecular weight? Discuss your results