Experiment 81

Objective

To prepare ammonia gas in the laboratory for experimental purposes.

Introduction

Ammonia can be generated in the laboratory by heating ammonium chloride with a base such as calcium oxide. The reaction releases ammonia gas, calcium chloride, and water vapor.

Reaction:

2NH4​Cl (s) + CaO (s) → 2NH3 (g) + CaCl2​ (s) + H2​O (g)

Materials

Chemicals

·       Ammonium chloride (NH₄Cl)

·       Calcium oxide (CaO)

Apparatus

·       Flask

·       Stand

·       Emitting tube

·       Gas collection jar

Reagents

·       3.659 g of ammonium chloride

·       Twice the weight of calcium oxide

Procedure

1.    Place ammonium chloride and twice its weight of calcium oxide in a flask.

2.    Cover the flask with a cork fitted with an emitting tube.

3.    Heat the flask using a Bunsen burner to start the reaction.

4.    Insert the other end of the emitting tube into a container with calcium oxide to dry the ammonia gas.

5.    Position a gas jar over the emitting tube to collect the ammonia gas.

6.    Continue heating until sufficient gas is collected.

7.    To purify the ammonia, pass it through substances such as sulfuric acid, phosphorus pentoxide, and additional calcium oxide.

Observation

The production of ammonia gas is noted by its characteristic pungent odor.

Questions

1.    What is ammonia?

2.    How is ammonia produced in this reaction?

3.    How is ammonia purified in the laboratory?

4.    What reagents are used for ammonia production in this experiment?