You and your lab partner place 2 g slices of liver into 3 test tubes containing water, vinegar, or baking soda. You add 15 ml of hydrogen peroxide to each and measure the amount of oxygen produced every 30 seconds for 3 minutes. Now that you have completed the experiment, you need to graph your results. You decide to make a triple line graph showing the rate of reaction (oxygen produced/30 sec.) for each of the three solutions. On your graph, where should you put the oxygen production?
A) on the y axis because it is the dependent variable
B) on the x axis because it is the dependent variable.
C) on the x axis because it is the independent variable
D) on the y axis because it is the independent variable

In a Cartesian plane, the dependent variable will always be placed on the y axis, while the dependent variable will always be on the x axis. Since oxygen production in the experiment shown in the above question is a dependent variable, it must be placed on the y axis. Now let's understand what makes oxygen production a dependent variable.

The dependent variable is one that can be measured and verified, but cannot show results on its own. The precise dependent variable undergoes the action of the independent variable to show results. As you may be asked in the question above, oxygen production in each test tube is a measurable variable that depends on the influence of the 15 ml hydrogen peroxide and its composition (water, vinegar or sodium bicarbonate). For this reason, oxygen production can be considered the dependent variable of this experiment.