Phenol red indicator changes from yellow to red in the pH range from 6.6 to 8.0. State what color the indicator will assume in the following solution: 0.20 M KOH
A) red
B) yellow
C) red-yellow mixture
D) orange
E) The indicator keeps its original colour.

Question

Quizplus · Accepted Answer

KOH is a strong base and will completely dissociate in water to form OH- ions, which will increase the pH of the solution to above 8.0. Phenol red will therefore assume its red color, indicating a basic pH.

Phenol Red Indicator Changes from Yellow to Red in the PH