A solution of one part of egg albumen mixed with two parts of water in a test tube is used to test for what?

It is a test to check the protein's solubility.

Explanation:

Proteins have varying levels of solubility and it is necessary to carry out tests that prove in which aqueous media the proteins are more likely to have high levels of solubility. This facilitates the execution of scientific works that develop products that work with proteins.

The level of solubility of proteins depends on the distribution of the polar and nonpolar groups of this molecule.

The most common test is done by adding water and protein to a beaker. An example of this is done by adding part of egg albumin mixed with two parts of water.

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: