Ammonia and Nitric Acid Formulae Properties Preparation

Download PDF

Uses of Ammonia

Ammonia is a colourless and foul-smelling gas which is composed of hydrogen and nitrogen. It is a simple and stable compound of both these elements and acts as a starting material to produce several nitrogen compounds. It is also amongst the most commonly present hydrides in the atmosphere. The amount of ammonia in the atmosphere is developed mostly because of the bacterial decomposition that is released from the nitrogen-rich elements from plants and animals. 

Azane is the IUPAC name of ammonia. The ammonia chemical formula is NH3. Ammonia is present all around us and we are all exposed to a lower concentration of it in our day to day activities. In this article, we will study the properties and preparation of ammonia and nitric acid, the uses of ammonia, ammonium carbonate uses, and the properties of ammonia.

Preparation Of Ammonia

Smaller quantities of ammonia are present in the air and soil because of the decay of the nitrogenous organic matter. To produce ammonia on a small scale, ammonium salts and caustic soda are made to react with each other.

2NH4Cl  +  Ca(OH)2    →      2NH3 +  2H2O +  CaCl2

For a large scale production, Haber’s process is used. The steps that are involved in Haber’s process are:

N2(g) + 3H2(g) ↔ 2NH3 (g)

Nitrogen and hydrogen are used in the form of raw materials for this reaction. The impurities for the gases get removed by a process known as scrubbing.

After this process of scrubbing, the gases are combined and then passed through a compressor. Then the mixture is compressed under a 200 atm pressure.

Then the compressed gases are passed to a converter in which the gases are heated up at a temperature of 450°C and 200 atm pressure. The nitrogen then tends to react with the hydrogen and forms ammonia, however, just about 15% of the total gas is formed.

The mixture of ammonia, nitrogen, and hydrogen is then removed from the converter and cooled wherein it tends to liquefy in the tank and then collected.

[Image will be uploaded soon]

Physical Properties of Ammonia

Ammonia Chemical Formula



Colourless gas


Strong and pungent odour

Ammonia Melting point

−77.73 °C or −107.91 °F or 195.42 K

Ammonia Boiling Point

−33.34 °C or −28.01 °F or 239.81 K

Ammonia Density

0.86 kg/m3

Chemical Properties of Ammonia

  1. Ammonia is highly soluble in water. The NH3 aqueous solution is a weak base since OH- ions get formed.

NH3 + H2O →  N4+ + OH-

  1. Ammonium salts get formed when ammonia reacts with an acid.

ZnSO4 + 2NH4OH (g) →  Zn(OH)2 + (NH4)2SO4

Uses of Ammonia

  1. The liquid ammonia includes being used as a refrigerant.

  2. The ammonia gas uses include the manufacturing of urea which is excellent nitrogen fertilizer.

  3. The ammonia solution uses include removing grease since it has cleansing properties.

Nitric Acid

Friedrich Wilhelm Ostwald in the starting of the 20th century had developed a process wherein ammonia was used for obtaining nitric acid. Due to the development of nitric acid, it had helped the Germans in World War I for making explosives and not importing it from other countries such as Chile. The chemical formula of nitric acid is denoted by HNO3.

Preparation of Nitric Acid

For the small scale preparation, nitric acid is made when concentrated sulphuric acid is heated along with NaNO3 or KNO3.

NaNO3 + H2SO4    →        NaHSO4 + HNO3

For the large scale preparations of nitric acid, the Ostwald process is used.

In this process, ammonia undergoes catalytic oxidation through oxygen present in the atmosphere. This happens in the presence of Pt/Rh in the form of a catalyst at 500 K temperature and a pressure of 9 bars.

4NH3 + 5O2     →     4NO(g) + 6H2O

The nitric oxide obtained is then reacted with the oxygen to form NO2.

2NO + O2 →    2NO2(g)

The NO2 formed is then made to dissolve in H2O which forms HNO3.

3NO2 (g) + H2O(l)    →    2HNO3(aq) + NO(g)

Properties of HNO3

  1. Nitric acid is colourless in nature.

  2. The boiling point of liquid nitric acid is 84.1°C and it tends to freeze at -41.55 °C and forms a white solid.

  3. It is a strong acid that dissociates and forms nitrate ion and hydronium.

HNO3(aq) +H2O (l)     →    H3O+(aq) + NO3-(aq)

  1. Nitric acid in its concentrated state tends to act as a strong oxidising state

Cu + 4HNO3   →  Cu(NO3)2 + 2NO2 + 2H2O

FAQ (Frequently Asked Questions)

1. What is Ammoniacal Nitrogen?

Ans: Ammoniacal nitrogen, denoted by NH3 - N, is a measure that is often used in determining the quantity of the ammonium ions. These are derived naturally from ammonia and returned to ammonia with the help of organic processes, either in water or waste liquids. This is a measure which is used mainly to quantify values in the water purification systems and waste treatment, and also as a measure of natural and man-made water reserves health. It is measured in mg/L.

2. Is Ammonia toxic?

Ans: The toxicity of ammonia generally does not tend to cause troubles for humans and other animals. This is because there exists a mechanism that prevents ammonia buildup in the blood. Ammonia gets converted to carbamoylphosphate by an enzyme called carbamoyl phosphate synthetase. This enters the urea cycle which either gets incorporated into amino acids or gets excreted in the urine. Amphibians and fishes do not have this mechanism since they usually tend to eliminate ammonia by excretion. Even the dilute concentrations of ammonia can be proven to be toxic to marine life, which is why it is regarded as dangerous for the environment. Ammonia also makes for a constituent of the tobacco smoke.

Share this with your friends