How does phenolphthalein appear in an acidic solution?
Answer and explanation
Correct answer: Colourless
Phenolphthalein is an acid-base indicator whose visible colour depends on the acidity of the solution. In an acidic medium, and also in the nearly neutral range used in school tests, phenolphthalein remains colourless because its coloured alkaline form is not produced. Therefore option B is correct. Pink is observed in a sufficiently basic solution, while blue and green are not its characteristic colours.
Frequently asked questions
What is the correct answer to this question?
Colourless
Why is this the correct answer?
Phenolphthalein is an acid-base indicator whose visible colour depends on the acidity of the solution. In an acidic medium, and also in the nearly neutral range used in school tests, phenolphthalein remains colourless because its coloured alkaline form is not produced. Therefore option B is correct. Pink is observed in a sufficiently basic solution, while blue and green are not its characteristic colours.
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.
