Question

when biuret reagent is added to a solution containing protein, the solution turns pink or purple. in the absence of protein, the solution is blue. biuret reagent was added to solutions that may or may not contain protein. the data can be seen in the table below. what is the independent variable in this experiment?

Answer 1

The independent variable in the experiment where Biuret reagent is added to test for the presence of proteins is the presence or absence of protein in the solutions.

Step-by-step explanation:

In the experiment described, where Biuret reagent is added to solutions to test for the presence of proteins, the independent variable is the component or condition that is manipulated or changed by the researcher to observe the effect on the dependent variable.

The independent variable would be the presence or absence of protein in the solutions being tested. When Biuret reagent is added, the solution turns pink or purple if proteins are present and remains blue if they are not. This reaction demonstrates that the independent variable in this experiment is the content of the solution—whether or not it contains protein—which determines the color change observed.