Magnesium gives a gas in an acidic solution, but calcium carbonate gives a different gas in the same solution. Which pair is correct?
Answer and explanation
Correct answer: Hydrogen from magnesium and carbon dioxide from calcium carbonate
A metal such as magnesium reacts with a dilute acid by displacing hydrogen: Mg + 2HCl → MgCl₂ + H₂. A carbonate reacts with an acid to produce a salt, water, and carbon dioxide: CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂. Hence magnesium gives hydrogen while calcium carbonate gives carbon dioxide, so option B is correct.
Frequently asked questions
What is the correct answer to this question?
Hydrogen from magnesium and carbon dioxide from calcium carbonate
Why is this the correct answer?
A metal such as magnesium reacts with a dilute acid by displacing hydrogen: Mg + 2HCl → MgCl₂ + H₂. A carbonate reacts with an acid to produce a salt, water, and carbon dioxide: CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂. Hence magnesium gives hydrogen while calcium carbonate gives carbon dioxide, so option B is correct.
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.
