Preparation of dry carbon dioxide in laboratory?

Dry carbon dioxide can be prepared in the laboratory by reacting a carbonate salt with a strong acid. Here is a simple method to prepare dry carbon dioxide:

Materials needed:
- Calcium carbonate (marble chips or limestone)
- Hydrochloric acid
- Gas collection apparatus (such as a gas syringe or gas collection tube)
- Drying agent (such as anhydrous calcium chloride or silica gel)

Procedure:
1. Place a small amount of calcium carbonate (marble chips or limestone) in a gas collection apparatus.
2. Add hydrochloric acid to the calcium carbonate in the gas collection apparatus. The reaction between calcium carbonate and hydrochloric acid will produce carbon dioxide gas.
3. Collect the carbon dioxide gas by displacement of water in a gas syringe or gas collection tube.
4. To dry the carbon dioxide gas, pass it through a drying agent such as anhydrous calcium chloride or silica gel. This will remove any moisture from the gas.
5. Collect the dry carbon dioxide gas in a gas collection apparatus for further use.

Safety precautions:
- Wear appropriate personal protective equipment, such as gloves and safety goggles, when handling chemicals.
- Perform the experiment in a well-ventilated area or in a fume hood to prevent exposure to harmful gases.
- Handle acids and bases with care to avoid skin irritation or burns.
- Do not inhale the carbon dioxide gas directly, as it can displace oxygen in the air and cause asphyxiation.

Note: This method is for educational purposes only and should be conducted under the supervision of a trained professional.

Materials:

- Sodium bicarbonate (NaHCO3)
- Hydrochloric acid (HCl)
- Funnel
- Filter paper
- Test tube
- Delivery tube
- Gas collecting jar

Procedure:

1. Set up the apparatus: Fill the funnel with filter paper and place it in the neck of the test tube. Connect the delivery tube to the test tube and insert the other end into the gas collecting jar inverted over a water bath.
2. Add sodium bicarbonate and hydrochloric acid: Carefully add a few grams of sodium bicarbonate to the test tube. Then, slowly add concentrated hydrochloric acid until the reaction begins.
3. Generate the gas: The reaction between sodium bicarbonate and hydrochloric acid produces carbon dioxide gas. The gas will bubble out and fill the gas collecting jar.
4. Collect the dry carbon dioxide: As the gas displaces the water in the gas collecting jar, it is collected in the dry part of the jar.
5. Test the gas: Test the collected gas with a lighted match. If the match goes out, it indicates the presence of carbon dioxide.

Chemical Equation:

```
NaHCO3 + HCl → NaCl + H2O + CO2
```

Safety Precautions:

- Wear gloves and safety glasses while working with chemicals.
- Perform the reaction in a well-ventilated area.
- Use caution when adding hydrochloric acid to avoid splashing.
- Do not seal the gas collecting jar while collecting the gas as it could create pressure and cause the jar to explode.