Draw a diagram of laboratory preparation of ammonia gas and label the lime tower and gas jar. Also write the balanced chemical equation involved in this process.

NH₄Cl+Ca(OH)₂HeatingLime tower (Ca(OH)₂) absorbs HCl fumes; NH₃ collected over wNH₃+CaCl₂+H₂O

Laboratory Preparation of Ammonia Gas

Ammonia gas ($\mathrm{NH}{}_3$) is prepared in the laboratory by heating a mixture of ammonium chloride ($\mathrm{NH}{}_4\mathrm{Cl}$) and calcium hydroxide ($\mathrm{Ca}(\mathrm{OH}){}_2$), commonly known as slaked lime. The apparatus used for this preparation consists of the following key components:

1. Round-bottom flask: Contains a mixture of $\mathrm{NH}{}_4\mathrm{Cl}$ and $\mathrm{Ca}(\mathrm{OH}){}_2$.
2. Delivery tube: Carries the produced ammonia gas to the lime tower.
3. Lime tower: Filled with calcium hydroxide solution to remove impurities like hydrogen chloride gas ($\mathrm{HCl}$) and moisture.
4. Gas jar: Collects the purified ammonia gas by downward displacement of air (since ammonia is lighter than air).

Procedure

• A mixture of $\mathrm{NH}{}_4\mathrm{Cl}$ and $\mathrm{Ca}(\mathrm{OH}){}_2$ is taken in a round-bottom flask.
• The flask is gently heated.
• Ammonia gas is produced, which passes through the delivery tube into the lime tower.
• The lime tower removes impurities, and the purified ammonia gas is collected in a gas jar by downward displacement of air.

ammoniaammonia

Balanced Chemical Equation

The reaction between ammonium chloride and calcium hydroxide can be represented as:

$$2\mathrm{NH}{}_4\mathrm{Cl}+\mathrm{Ca}(\mathrm{OH}){}_2\to 2\mathrm{NH}{}_3+\mathrm{CaCl}{}_2+2\mathrm{H}{}_2\mathrm{O}$$

Safety Precautions

• The apparatus should be set up properly to avoid leakage.
• Ammonia gas is harmful if inhaled in large quantities, so the experiment should be conducted in a well-ventilated area.
• The gas jar should be inverted over water to collect ammonia safely.