A gas turns lime water milky and in excess removes the milkiness. This gas is most likely formed from what?
Answer and explanation
Correct answer: Reaction of acid and carbonate
The gas is carbon dioxide. First, carbon dioxide reacts with lime water, calcium hydroxide, to form insoluble calcium carbonate, which produces the milky appearance. When carbon dioxide is passed in excess, the precipitate changes into soluble calcium hydrogen carbonate. Acids reacting with carbonates release carbon dioxide, so option A is correct; the other reactions do not normally produce this gas.
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What is the correct answer to this question?
Reaction of acid and carbonate
Why is this the correct answer?
The gas is carbon dioxide. First, carbon dioxide reacts with lime water, calcium hydroxide, to form insoluble calcium carbonate, which produces the milky appearance. When carbon dioxide is passed in excess, the precipitate changes into soluble calcium hydrogen carbonate. Acids reacting with carbonates release carbon dioxide, so option A is correct; the other reactions do not normally produce this gas.
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.
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