Question #1730e
1 Answer
Feb 2, 2018
Mostly so you can know how much you have and that it is all oxygen instead of having air mixed in it.
Explanation:
Since you can't see air or oxygen gas, you need a way to know when your container is full. The oxygen (or any gas you choose) will push the water out as it fills the container. You then know that it is only oxygen (and a little water vapor) instead of having a mixture of oxygen and air.
A person could try to fill a plastic bag that was originally flat but it is more difficult. A balloon would require that the oxygen be pressurized enough to blow up the balloon and that isn't likely to happen with a normal method of making it by a chemical reaction.
