In this experiment, we measured the mass of 4 gasses; oxygen, carbon dioxide, helium, and lab gas. We took a Ziplock bag, and turned into a non-stretchy balloon, and filled with each gas and measured the apparent mass then calculated the actual mass, then find a ratio between the mass of oxygen and the other gasses. We tried to keep the pressure about the same each time so our calculations would be more accurate.
We found out that the heaviest was carbon dioxide, and the lightest was helium. In fact, helium and lab gas had a density below 0. Anyways, it turned out that our apparent masses were very different from our actual mass calculations; for example oxygen’s apparent mass was 28.33g but its actual mass was 4.10g. We also found the ratios, and after collecting class data, our carbon dioxide ratio was 1.39/1g, our helium ratio was .21/1g, and our lab gas ratio was .59/1g.
Then we had to come up with two hypotheses to figure out why one gas is heavier (denser) than another? Well, we came up with hypothesis #1: The different molecule mass hypothesis, and hypothesis #2: The more molecules in the same volume hypothesis. After having a class discussion, turns out that hypothesis one is more reliable due to Avogadro’s hypothesis; if two gasses at the same temperature and equal volume contain equal amount of molecules. So according to the statement above, the carbon dioxide molecules must be 1.39x bigger than an oxygen molecule, a helium molecule must be .21x bigger, and .59x bigger than an oxygen