A metal carbonate reacts with a solution X which forms a salt, water and a gas Y. What are X and Y ?
Generated by claude-sonnet-4-6 · 2026-06-14 10:31 · grounding rag
Model Answer
(C) X – Hydrochloric acid, Y – Carbon dioxide
When a metal carbonate reacts with an acid (HCl), it produces a salt, water, and CO₂ gas. Example: $\text{CaCO}_3 + 2\text{HCl} \rightarrow \text{CaCl}_2 + \text{H}_2\text{O} + \text{CO}_2$
Explanation
- Metal carbonates react with acids, not bases like NaOH — this eliminates options A and B.
- The gas released is always CO₂ (not H₂) when a carbonate reacts with an acid — this eliminates option D.
- Remember the pattern: Carbonate + Acid → Salt + Water + CO₂↑