If blue litmus turns red and methyl orange turns red in a solution, which substance can neutralise it?
Answer and explanation
Correct answer: Sodium hydroxide solution
Both observations identify the test solution as acidic: blue litmus turns red in acid, and methyl orange is red in a sufficiently acidic medium. Neutralisation requires an acid to react with a base, forming salt and water. Sodium hydroxide solution is a base and supplies hydroxide ions that combine with hydrogen ions. Lemon juice, vinegar, and hydrochloric acid are acidic, so they would not appropriately neutralise this solution. Therefore option A is correct.
Frequently asked questions
What is the correct answer to this question?
Sodium hydroxide solution
Why is this the correct answer?
Both observations identify the test solution as acidic: blue litmus turns red in acid, and methyl orange is red in a sufficiently acidic medium. Neutralisation requires an acid to react with a base, forming salt and water. Sodium hydroxide solution is a base and supplies hydroxide ions that combine with hydrogen ions. Lemon juice, vinegar, and hydrochloric acid are acidic, so they would not appropriately neutralise this solution. Therefore option A is correct.
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.
