Which of the following is not an indicator that occurs naturally?
Answer & explanation
Correct answer: option 4
The correct answer is option 4. Phenolphthalein.
Phenolphthalein is not an indicator that occurs naturally. It is a synthetic chemical compound commonly used as a pH indicator in laboratory and educational settings. The other options mentioned—Gudhal (Hibiscus), Turmeric, and Litmus—are natural indicators.
Therefore, the correct option is Phenolphthalein.