Under careful and controlled supervision, Ashley is slowly adding 1 mL of a strong acid at a time to 30 mL of a strong base to measure the effect it had on the pH. What is the testing (independent) and outcome (dependent) variable of this experiment? What would a good control be?

The independent variable is the volume of the strong acid added to the strong base

The dependent variable is the effect of the combination of the acid and base on the pH

Explanation:

The given parameters are;

The rate at which Ashley is adding the strong acid to the strong base = 1 mL per each time

The volume of the strong base to which Ashley is adding the acid = 30 mL

Therefore;

The testing, or independent variable of the experiment = The number of 1 mL volume of the strong acid Ashley adds to the strong base

The outcome, or dependent variable of the experiment = The measured (change) effect on the pH.