We know that egg shell is mostly made up of Calcium Carbonate and when calcium carbonate is react with nitric acid it produce calcium nitrate, carbon dioxide gas and water. When carbon dioxide gas is passed through lime water it turns in to white precipitate solution. Since egg shell slowly dissolve and become disappear, when it is added to nitric acid.
The reaction is follows as:
CaCO₃ + 2HNO₃ → Ca(NO₃)₂ + CO₂ + H₂O
After that, the egg is slowly dissolved in nitric acid and forms calcium nitrate with carbon dioxide bubbles and water. At last egg shell disappears.
How to test whether this gas is co2
When we pass the carbon dioxide gas in to lime water solution Ca(OH)₂ then it forms calcium carbonate CaCO₃ ( white precipitate solution ) and water which confirms that it is carbon dioxide ( co2 ) gas molecule. Here is the chemical reaction.
CO₂ + Ca(OH)₂ → CaCO₃ + H₂O
