Which observation suggests that a base may be present in a solution?
Answer and explanation
Correct answer: Red litmus turns blue
Litmus is an acid-base indicator. A basic solution changes red litmus paper to blue because the indicator responds to the alkaline medium. Blue litmus turning red instead indicates an acid. Limewater becoming milky is associated with carbon dioxide reacting with calcium hydroxide, while a pop sound from a burning splint tests for hydrogen gas. Thus only option A is evidence of a possible base.
Frequently asked questions
What is the correct answer to this question?
Red litmus turns blue
Why is this the correct answer?
Litmus is an acid-base indicator. A basic solution changes red litmus paper to blue because the indicator responds to the alkaline medium. Blue litmus turning red instead indicates an acid. Limewater becoming milky is associated with carbon dioxide reacting with calcium hydroxide, while a pop sound from a burning splint tests for hydrogen gas. Thus only option A is evidence of a possible 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.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
