Ammonia gas can be easily collected by the downward displacement of water due to its lower density compared to water. Here's how you can set up this method:

Materials Needed:

- Glass jar or beaker with a wide opening

- Delivery tube or gas collection tube

- Rubber stopper

- Pneumatic trough (a large water-filled container)

Procedure:

1. Fill the pneumatic trough with water and place it on a stable surface.

2. Take the glass jar or beaker and fill it with water until it is about one-third full.

3. Connect the delivery tube to the rubber stopper, making sure the connection is airtight. Insert the other end of the delivery tube into the water-filled glass jar.

4. Position the delivery tube so that the open end is near the bottom of the glass jar, but not touching the water.

5. Start producing ammonia gas by your preferred method (e.g., heating ammonium chloride with sodium hydroxide).

6. As ammonia gas is generated, it will travel through the delivery tube and begin to displace the water in the glass jar.

7. The ammonia gas will rise and collect in the upper portion of the glass jar, while the water level decreases.

8. Continue collecting the ammonia gas until the glass jar is nearly full or until the gas production ceases.

9. Once the collection is complete, carefully remove the glass jar from the pneumatic trough, making sure not to spill the water.

Note:

- Ammonia gas is lighter than air and has a pungent odor. Therefore, it is essential to conduct this experiment in a well-ventilated area and avoid direct inhalation of the gas.

- Always wear appropriate safety gear, such as gloves and eye protection, when working with chemicals and gases.

- Properly dispose of any waste or chemicals used in the experiment according to local regulations.

By following this method, you can successfully collect ammonia gas in a water-filled glass jar using the principle of water displacement.