A solution gives one gas with zinc and another gas with sodium carbonate. What is the correct identification of both gases?
Answer and explanation
Correct answer: Hydrogen from zinc and carbon dioxide from sodium carbonate
The governing concept is the characteristic reaction of an acid with a metal and with a carbonate. Zinc displaces hydrogen from an acid: Zn + 2HCl → ZnCl₂ + H₂. A carbonate reacts with acid to form salt, water, and carbon dioxide: Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂. Thus the first gas is hydrogen and the second is carbon dioxide. The reverse identification and oxygen or chlorine choices do not match these reactions.
Frequently asked questions
What is the correct answer to this question?
Hydrogen from zinc and carbon dioxide from sodium carbonate
Why is this the correct answer?
The governing concept is the characteristic reaction of an acid with a metal and with a carbonate. Zinc displaces hydrogen from an acid: Zn + 2HCl → ZnCl₂ + H₂. A carbonate reacts with acid to form salt, water, and carbon dioxide: Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂. Thus the first gas is hydrogen and the second is carbon dioxide. The reverse identification and oxygen or chlorine choices do not match these reactions.
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.
