To Prepare Ammonia Gas And Study Its Properties. | Grade Xi

HN-Admin - Wed Dec 27 2023

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APPARATUS REQUIRED:

Kipp's apparatus or a suitable flask with a side tube and delivery tube
Rubber tubing
Glass jar or beaker
Litmus paper
Hydrochloric acid (1 M)
Sodium hydroxide (1 M)
Phenolphthalein indicator
Graduated cylinder
Thermometer
Safety goggles
Gloves

CHEMICALS REQUIRED:

Ammonium chloride (NH4Cl)
Calcium hydroxide (Ca(OH)2)

THEORY:

Ammonia (NH3) is a colorless, pungent, and toxic gas with a characteristic odor. It is produced naturally by the anaerobic decomposition of organic matter and is also a byproduct of some industrial processes. Ammonia is a weak base and can react with acids to form ammonium salts.

PROCESS:

Set up the Kipp's apparatus or flask according to the diagram.
Add 10 g of ammonium chloride (NH4Cl) to the flask.
Add 10 mL of sodium hydroxide (1 M) to the flask.
Carefully add a small piece of calcium hydroxide (Ca(OH)2) to the flask.
Connect the rubber tubing to the side tube of the flask and the delivery tube to a glass jar or beaker.
Open the stopcock on the Kipp's apparatus or flask to allow the ammonia gas to flow into the jar or beaker.
Collect the ammonia gas in the jar or beaker by holding it upside down over the delivery tube.
Test the properties of the ammonia gas by dipping a piece of litmus paper into the jar or beaker.
Add a few drops of hydrochloric acid (1 M) to the jar or beaker containing the ammonia gas.
Test the pH of the solution in the jar or beaker using phenolphthalein indicator.
Measure the temperature of the solution in the jar or beaker using a thermometer.

OBSERVATIONS:

The ammonia gas is a colorless, pungent gas with a characteristic odor.
The litmus paper turns blue when dipped into the ammonia gas, indicating that the gas is a base.
When hydrochloric acid is added to the ammonia gas, a white precipitate of ammonium chloride (NH4Cl) forms.
The phenolphthalein indicator turns pink when added to the solution in the jar or beaker, indicating that the solution is basic.
The temperature of the solution in the jar or beaker increases when the ammonia gas is added.

OBSERVATION TABLE:

Observation	Description
Color of ammonia gas	Colorless
Odor of ammonia gas	Pungent
Litmus paper test	Blue
Hydrochloric acid test	White precipitate of ammonium chloride (NH4Cl)
Phenolphthalein indicator test	Pink
Temperature of solution	Increases

CALCULATIONS:

The amount of ammonia gas produced can be calculated using the following equation:

n = m/M

where:

n is the number of moles of ammonia gas produced
m is the mass of ammonium chloride (NH4Cl) used
M is the molar mass of ammonium chloride (NH4Cl)

The molar mass of ammonium chloride (NH4Cl) is 53.49 g/mol.

Therefore, the number of moles of ammonia gas produced is:

n = 10 g / 53.49 g/mol = 0.187 mol

The volume of ammonia gas produced can be calculated using the following equation:

V = nRT

where:

V is the volume of ammonia gas produced
n is the number of moles of ammonia gas produced
R is the gas constant (0.0821 L·atm/(mol·K))
T is the temperature of the gas in Kelvin

The temperature of the gas is assumed to be room temperature (25°C or 298 K).

Therefore, the volume of ammonia gas produced is:

V = 0.187 mol × 0.0821 L·atm/(mol·K) × 298 K = 4.28 L

RESULTS:

Ammonia gas is a colorless, pungent, and toxic gas with a characteristic odor. It is a weak base and can react with acids to form ammonium salts. The amount of ammonia gas produced was 0.187 mol and the volume of ammonia gas produced was 4.28 L.

PRECAUTIONS:

Ammonia gas is toxic and should be handled with care.
Wear safety goggles and gloves when working with ammonia gas.
Work in a well-ventilated area.
Do not inhale ammonia gas.
Do not allow ammonia gas to come into contact with skin or eyes.
If ammonia gas is inhaled or comes into contact with skin or eyes, flush the affected area with water and seek medical attention immediately.