I admittedly don’t know much basic science. I never took biology, I only had a year of environmental science and a few months of physics in high school. I was always intimidated by it. So all I know now has been learned by reading up on subjects that interest me, and watching documentaries! As a result, I love doing hands-on science experiments.
The kids and I did an experiment just now. We put vinegar and baking soda in a bottle and put a balloon over the top. I had seen a meme on pinterest that said it would make the balloons lighter than air, much like helium! To our amusement, the balloon immediately began filling up. But when we tied it off, we were surprised to see it fall to the floor rather quickly! So I did some quick research on my phone and learned that when baking soda and vinegar mixes, it creates carbon dioxide. http://scienceline.ucsb.edu/getkey.php?key=4147 But I was confused, because this balloon fell much faster than a balloon blown up by breathing into it; and I had always been told that humans expel carbon dioxide. So what was different? More research revealed that humans actually expel a mixture of gasses. Carbon dioxide only comprises about 5-6% of this mixture! That came as quite a shock to me. Apparently, 78% of the mixture is actually nitrogen; the rest being oxygen and a little argon. http://en.m.wikipedia.org/wiki/Breathing Upon further reading, I discovered that while nitrogen is about 3% lighter than air, carbon dioxide is slightly more dense than air. http://en.m.wikipedia.org/wiki/Lighter_than_air http://en.m.wikipedia.org/wiki/Carbon_dioxide Meaning that balloons inflated by your breath will float ever so slightly, and a balloon inflated via a baking soda and vinegar reaction will fall almost as quickly as a solid object.
There you go! You learn something new every day, if you let your curiosity run wild =)