An indicator shows red in acidic solution and yellow in basic solution. Which indicator could it be?
Answer and explanation
Correct answer: Methyl orange
Methyl orange is a synthetic acid-base indicator with a transition range in which it appears red in an acidic medium and yellow in a basic or sufficiently alkaline medium. Therefore option B matches both observations. Phenolphthalein is colourless in acid and pink in base; blue litmus changes to red in acid but does not become yellow in base; turmeric usually changes from yellow to reddish-brown in a base.
Frequently asked questions
What is the correct answer to this question?
Methyl orange
Why is this the correct answer?
Methyl orange is a synthetic acid-base indicator with a transition range in which it appears red in an acidic medium and yellow in a basic or sufficiently alkaline medium. Therefore option B matches both observations. Phenolphthalein is colourless in acid and pink in base; blue litmus changes to red in acid but does not become yellow in base; turmeric usually changes from yellow to reddish-brown in a base.
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.
