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: 0.10 M NaCN
A) red
B) yellow
C) red-yellow mixture
D) The indicator is its original color.
E) There is not enough information to answer this question.

Question

Quizplus · Accepted Answer

NaCN is a salt of a weak acid (HCN) and a strong base (NaOH), which means it will create a basic solution. The pH of a 0.10 M NaCN solution will likely be above 8.0, causing the phenol red indicator to turn red.

Phenol Red Indicator Changes from Yellow to Red in the PH