Which of the following substances acts as an olfactory indicator?
Answer and explanation
Correct answer: Onion (प्याज)
An olfactory indicator is a substance whose smell changes in an acidic or basic medium. Onion is a standard example: its characteristic smell is altered or becomes difficult to detect in a basic solution, so option A is correct. Turmeric, litmus and phenolphthalein are mainly visual indicators because they show colour changes rather than a smell-based change. The distinguishing clue is the word “olfactory,” which relates to the sense of smell.
Frequently asked questions
What is the correct answer to this question?
Onion (प्याज)
Why is this the correct answer?
An olfactory indicator is a substance whose smell changes in an acidic or basic medium. Onion is a standard example: its characteristic smell is altered or becomes difficult to detect in a basic solution, so option A is correct. Turmeric, litmus and phenolphthalein are mainly visual indicators because they show colour changes rather than a smell-based change. The distinguishing clue is the word “olfactory,” which relates to the sense of smell.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
