A substance turns red litmus blue but is only slightly soluble in water. What is the more correct term for it?
Answer and explanation
Correct answer: Base
A base is a substance that can neutralise an acid, whereas an alkali is specifically a base that dissolves in water to give hydroxide ions. Turning red litmus blue indicates basic character, but the statement says the substance is only slightly soluble. Therefore the broader and safer term is base. An alkali would require clear water solubility; a strong acid would show the opposite litmus change.
Frequently asked questions
What is the correct answer to this question?
Base
Why is this the correct answer?
A base is a substance that can neutralise an acid, whereas an alkali is specifically a base that dissolves in water to give hydroxide ions. Turning red litmus blue indicates basic character, but the statement says the substance is only slightly soluble. Therefore the broader and safer term is base. An alkali would require clear water solubility; a strong acid would show the opposite litmus change.
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.
