Chemical Reactivity of Ammonia with Hydrogen

Ammonia, a colorless gas with a distinct odor, is a chemical building block that is used to make a variety of daily things. It can be found in the air, soil, and water, as well as in plants and animals, including humans.

Nitrogen is the first element in the periodic table’s group 15. In 1772, Daniel Rutherford discovered nitrogen. Nitrogen is found in a variety of chemicals, including nitric acid, nitrogen dioxide, ammonia, and ammonium hydroxide. The purpose of this article is to teach you everything you need to know about ammonia, including its structure, physical and chemical properties, preparation, manufacturing using Haber’s process, and applications.

Ammonia

Ammonia is a chemical made up of nitrogen and hydrogen. It has one nitrogen atom and three hydrogen atoms. Its chemical formula is H3 .

Ammonia is produced naturally by the decomposition of nitrogen compounds in animal and plant bodies when they die or decay, resulting in ammonia. Ammonia can also be found as ammonium salt in the soil.

Examples

Formation of ammonia by the decomposition of nitrogenous organic matter urea.

NH2CONH2+H2O yields→  NH42CO3 Yields⇔ 2NH3+CO2+H20 

Structure of Ammonia

The ammonia molecule is produced when three sp3 hybrid orbitals of nitrogen and three s orbitals of hydrogens collide. A lone pair of electrons occupy the 4thsp2 hybrid orbital of nitrogen. The ammonia molecule has a trigonal pyramidal structure as a result of this.

The angle between the H-N-H and the N-H bonds is 107.8 degrees, and the N-H bond length is 101.7 minutes. The H-N-H bond angle is somewhat smaller than the tetrahedral angle of 1090 28′ due to lone pair-bond pair repulsion, which tends to push the N-H bond slightly inwards109028′. Ammonia is linked in liquid and solid forms due to hydrogen bonding.

Reaction of Ammonia with Hydrogen

On a Commercial Scale, Generally Ammonia is manufactured by Haber’s Process.

N2+3H2 Yields⇔  2NH3;H0=-92.4kJmol

This is a reversible, exothermic reaction that occurs when the volume decreases. As a result, according to Le Chatelier’s principle, the best conditions for producing ammonia are:

1. Low temperature: Because the forward process is exothermic, the generation of ammonia is favored at low temperatures. The rate of reaction, however, will be slow at low temperatures. The reaction’s optimal temperature has been determined to be around 700K.

2. High pressure will favor the creation of ammonia since the forward reaction happens with a decrease in volume. At a pressure of 200×105Pa (200 atmospheres), the reaction is normally carried out.

3. Catalyst: The reaction rate is relatively slow, roughly 700K. As a catalyst, iron oxide is utilized, coupled with a little amount of K2 O and Al2 O3. The inclusion of molybdenum as a promoter increases the catalyst’s efficiency.

Haber’s process compresses a 1:3 molar ratio of N2 and H2 to around 200 atmospheric pressure. The compressed gasses are then sent through a soda lime tower to remove moisture and carbon dioxide after cooling.

Following that, these are fed into a catalyst chamber containing iron oxide, a little amount of K2 O and Al2 O3 .when the two gasses combine to form ammonia, the chamber is heated to 700K using electricity. Because the process is exothermic, the heat created maintains the proper temperature, and no extra electrical heating is required. Iron oxide is used as a catalyst, along with a minor amount of K2O andAl2O3. The addition of molybdenum as a promoter improves the efficiency of the catalyst.

The heat generated by the exothermic process keeps the temperature at the desired level, thus no extra electrical heating is required.

The gasses leaking from the chamber contain around 15–20 percent ammonia, with the balance being nitrogen and hydrogen that haven’t been reacted with. They flow via the condensing pipe, which liquefies and gathers the ammonia in the receptor. The unreacted gasses are fed back to the compression pump and mixed with a new gas mixture.

Uses of Ammonia

Ammonia has a variety of applications, including the following:

• In the production of nitric acid by Ostwald.

• The Solvay process is utilized in the production of sodium carbonate.

• It’s a component in rayon and urea manufacture.

• Fertilizers such as ammonium sulfate, ammonium nitrate, urea, diammonium phosphate, and others are manufactured.

• As a refrigerant in ice plants.

• It can be used to clean furniture and glass surfaces.

• It is used as a reagent and a solvent in the laboratory.

Conclusion

One of the most essential nitrogen molecules is ammonia. Ammonia: Preparation, Structure, Properties, and Uses is covered in the article. Its physical qualities, structure, and several preparation methods, with a focus on Haber’s method.

Apart from that, this article explains chemical features such as basic nature, Lewis base, combustion and oxidation, and ammonia usage.