Rank the four gases (air, exhaled air, gas produced from from decomposition of H2O2, gas from decomposition of NaHCO3) in order of increasing concentration of oxygen).

The concentration in this case will be expressed as mole oxygen per mole compound or mixture. In air, there are 42 moles of oxygen per 100 moles air. In exhaled air, there are 32 moles Oxygen per 100 moles ex. air. The decomposition of h2o2 results to 2 moles h2O and 1 mole oxygen. Hence there are 4 mole oxygen per 7 moles product. The decomposition of NaHCO3 results ot Na2CO3, Co2 and H20. there are 6 moles pxygen per 12 moles atoms. The ranking (increasing to decreasing) is decomposition of H2O2, decomposition of NaHCO3, air, and exhaled air.