NTA Abhyas JEE Main2020Chemistrys Block ElementsPractice
A solid compound X on heating gives C O 2 gas and a residue. The residue mixed with water forms Y. On passing an excess of C O 2 through Y in water, a clear solution Z is obtained. On boiling Z, compound X is reformed. The compound X is
Options
- AC a H C O 3 2
- BC a C O 3
- CN a 2 C O 3
- DK 2 C O 3
Correct answer
B. C a C O 3
Step-by-step solution
The given compound X must be C a C O 3 . It can be explained by following reaction C a C O 3 → Δ C a O + C O 2 ↑ C a O + H 2 O → C a O H 2 Y C a O H 2 + 2 C O 2 + H 2 O → C a H C O 3 2 Z C a H C O 3 2 → Δ C a C O 3 X + C O 2 ↑ + H 2 O