Turning lime water milky is a strong experimental indication for which gas?
Answer and explanation
Correct answer: Carbon dioxide
Carbon dioxide turns lime water milky because it reacts with aqueous calcium hydroxide to form insoluble calcium carbonate: CO₂ + Ca(OH)₂ → CaCO₃↓ + H₂O. The suspended calcium carbonate particles produce the milky appearance. Hydrogen, oxygen, and nitrogen do not normally give this characteristic limewater test, so they cannot explain the observed precipitate.
Frequently asked questions
What is the correct answer to this question?
Carbon dioxide
Why is this the correct answer?
Carbon dioxide turns lime water milky because it reacts with aqueous calcium hydroxide to form insoluble calcium carbonate: CO₂ + Ca(OH)₂ → CaCO₃↓ + H₂O. The suspended calcium carbonate particles produce the milky appearance. Hydrogen, oxygen, and nitrogen do not normally give this characteristic limewater test, so they cannot explain the observed precipitate.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Chemical Reactions and Equations.
