The indicator phenolphthalein changes from colorless to pink between pH 8.2 and pH 10. If phenolphthalein is added to a solution, and the solution remains colorless, then
A)the solution is acidic, and the pH must be at or below 7.0.
B)the pH of the solution must be below 8.2, and the solution is basic.
C)the pH of the solution must be below 8.2, but the solution could be either acidic or basic.
D)the pH of the solution must be above 10, and the solution is basic.
E)the pH of the solution is above 10, and the solution is acidic.

Question

Quizplus · Accepted Answer

The fact that the phenolphthalein did not change color indicates that the pH is below 8.2. However, it cannot be concluded whether the solution is acidic or basic without additional information.

The Indicator Phenolphthalein Changes from Colorless to Pink Between PH