An acid reacts with zinc to give one gas and with sodium carbonate to give another gas. What are the correct identities of the two gases?
Answer and explanation
Correct answer: Hydrogen from zinc and carbon dioxide from carbonate
The governing concept is the characteristic reaction of acids with metals and carbonates. Zinc, a sufficiently reactive metal, displaces hydrogen from a dilute acid: Zn + 2HCl → ZnCl₂ + H₂. Sodium carbonate reacts with an acid to produce a salt, water, and carbon dioxide: Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂. Therefore the gases are hydrogen and carbon dioxide respectively. Option A is correct; the reverse pairing in B is wrong.
Frequently asked questions
What is the correct answer to this question?
Hydrogen from zinc and carbon dioxide from carbonate
Why is this the correct answer?
The governing concept is the characteristic reaction of acids with metals and carbonates. Zinc, a sufficiently reactive metal, displaces hydrogen from a dilute acid: Zn + 2HCl → ZnCl₂ + H₂. Sodium carbonate reacts with an acid to produce a salt, water, and carbon dioxide: Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂. Therefore the gases are hydrogen and carbon dioxide respectively. Option A is correct; the reverse pairing in B is wrong.
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.
