If dry hydrogen chloride gas is passed over dry blue litmus paper, which conclusion is most correct?
Answer and explanation
Correct answer: Litmus will remain blue
Hydrogen chloride shows acidic behaviour only after dissolving in water and ionising to produce hydronium ions. Dry HCl gas passing over dry blue litmus has no available water, so the ions needed for the colour change are not formed and the paper remains blue. In moist conditions HCl would turn blue litmus red. Therefore option B is the precise conclusion.
Frequently asked questions
What is the correct answer to this question?
Litmus will remain blue
Why is this the correct answer?
Hydrogen chloride shows acidic behaviour only after dissolving in water and ionising to produce hydronium ions. Dry HCl gas passing over dry blue litmus has no available water, so the ions needed for the colour change are not formed and the paper remains blue. In moist conditions HCl would turn blue litmus red. Therefore option B is the precise conclusion.
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.
