Why does lime water turn milky when carbon dioxide gas is passed through it?
Answer and explanation
Correct answer: Due to formation of calcium carbonate
The governing concept is a precipitation reaction used to test carbon dioxide. Lime water contains calcium hydroxide, Ca(OH)₂. When CO₂ is passed through it, insoluble calcium carbonate forms: Ca(OH)₂ + CO₂ → CaCO₃ + H₂O. The suspended CaCO₃ makes the liquid milky, so option A is correct; the other products are not formed in this reaction.
Frequently asked questions
What is the correct answer to this question?
Due to formation of calcium carbonate
Why is this the correct answer?
The governing concept is a precipitation reaction used to test carbon dioxide. Lime water contains calcium hydroxide, Ca(OH)₂. When CO₂ is passed through it, insoluble calcium carbonate forms: Ca(OH)₂ + CO₂ → CaCO₃ + H₂O. The suspended CaCO₃ makes the liquid milky, so option A is correct; the other products are not formed in this reaction.
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.
