In a science experiment showing the splitting of water into Oxygen and hydrogen, two inverted test tubes of water were placed over the site of the reaction. (see the pic) How can you tell which one was catching the oxygen and which one was catching the hydrogen? Question 4 options: The hydrogen is a positive ion and will be located close to the negative terminal of the battery. The oxygen is a negative ion which will be located next to the negative terminal of the battery. There are 2 hydrogen atoms for every oxygen atom. The hydrogen will take up more space and is pushing the water lower in the test tube. The hydrogen, being a smaller atom, will take up less space than the oxygen. It will push the water down less.

There are 2 hydrogen atoms for every oxygen atom. The hydrogen will take up more space and is pushing the water lower in the test tube.

Explanation:

To find out what water is made of, we may have to look at its chemical formula, which is H2O. This basically tells us that the water molecule is composed of two elements: hydrogen and oxygen or, more precisely, two hydrogen atoms (H2) and one oxygen atom (O). Hydrogen and oxygen are gases at room temperature. Splitting water into its two components is much easier to do by a process called water electrolysis. Making hydrogen or oxygen this way seems simple. In water electrolysis, the source of energy used is electricity. An easy way to generate electricity is with a battery. Because pure water is not good at conducting electricity, however, electrolysis requires the addition of an electrolyte, such as salt or acid. The electrolyte dissolves in water and separates into ions (electrically charged particles) that move through the solutions and are able to conduct electricity this way.

As electrolysis progresses, the water level at the negative terminal becomes about half that of the positive terminal, meaning that we have collected double the amount of hydrogen gas compared with oxygen. The difference is due to the fact that one water molecule has two hydrogen atoms to one oxygen atom, as explained above. This means it takes two water molecules (2 H2O) to make one oxygen molecule (O2). At the same time, however, two molecules of water (2 H2O) can make two molecules of hydrogen (2 H2). Hence the answer.