name the gas evolved when dil. Hcl reacts with sodium hydrogen cabonate. how it is recongnised ?
I think you want this
NaHCO3 + HCl ----> NaCl + H2O + CO2
CO2 is the gas evolved.
It is colorless and odorless but will extinguish a burning flame.
When dilute hydrochloric acid (HCl) reacts with sodium hydrogen carbonate (NaHCO3), the gas that is evolved is carbon dioxide (CO2). Carbon dioxide is recognized by its physical and chemical properties.
To recognize the formation of carbon dioxide gas, you can perform the following steps:
1. Set up the reaction: Mix dilute hydrochloric acid (HCl) and sodium hydrogen carbonate (NaHCO3) in a test tube or a flask.
Equation: HCl + NaHCO3 → NaCl + CO2 + H2O
2. Observe the reaction: As the reaction proceeds, you will observe effervescence (bubbling) in the form of gas being released. This gas is carbon dioxide.
3. Test for carbon dioxide: There are a few ways to confirm the presence of carbon dioxide gas:
- Limewater test: Pass the gas evolved through limewater, which is a clear solution of calcium hydroxide (Ca(OH)2). Carbon dioxide will react with calcium hydroxide to form a white precipitate of calcium carbonate (CaCO3).
- Splint test: If you bring a burning splint near the gas, it should extinguish the flame since carbon dioxide is a non-combustible gas.
These methods will help you recognize the presence of carbon dioxide gas when dilute hydrochloric acid reacts with sodium hydrogen carbonate.