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(aq).
A)red
B)yellow
C)red-yellow mixture
D)orange
E)The indicator keeps its original color.

Question

Quizplus · Accepted Answer

Since KOH is a strong base, it will completely dissociate in water to form hydroxide ions (OH-) which will increase the pH of the solution. The pH will be above the range for which phenol red changes color, which means it will assume its red color to indicate the basic nature of the solution. Thus, the best choice is A) red.

Phenol Red Indicator Changes from Yellow to Red in the PH