Question

For the $pH$ range of 2.8 to 4.6, which indicator should be preferred?

• A. Phenolphthalein
• B. Methyl red
• C. Thymol blue
• D. Bromophenol blue

Hint:

Choose indicators whose pH range overlaps the solution's expected pH.

Answer 1

The Correct Option is D

Bromophenol blue has a pH transition range of approximately 3.0 to 4.6, making it ideal for detecting pH changes in the 2.8 to 4.6 range. Other indicators like phenolphthalein and methyl red operate in different pH ranges.