What type of substance turns blue litmus paper red?
Answer and explanation
Correct answer: Acid
Litmus is an acid–base indicator. In an acidic medium, blue litmus changes to red, so option A, acid, is correct. A base shows the opposite familiar change by turning red litmus blue. A neutral salt solution or water generally produces no characteristic litmus-colour change under ordinary conditions, so options C and D do not explain the stated observation.
Frequently asked questions
What is the correct answer to this question?
Acid
Why is this the correct answer?
Litmus is an acid–base indicator. In an acidic medium, blue litmus changes to red, so option A, acid, is correct. A base shows the opposite familiar change by turning red litmus blue. A neutral salt solution or water generally produces no characteristic litmus-colour change under ordinary conditions, so options C and D do not explain the stated observation.
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.
