Uses of Nitric Acid: Overview, Questions, Preparation

Nitric acid is a strong, colourless acid with the molecular formula HNO3. Also referred to as the spirit of Nitre and aqua Fortis, nitric acid is highly corrosive. This acid is usually colorless but may exhibit a light yellow colour as it gets older. The decomposition of nitric acid into oxides of nitrogen and water is what leads to it.

There is one nitrogen atom, three oxygen atoms, and one hydrogen atom present in nitric acid. Out of the three oxygen atoms, one shares a double bond with the nitrogen atom. The remaining two oxygen atoms share a single bond with both nitrogen and hydrogen atoms.

The nitrogen atom in the HNO3 molecule carries a charge of +1. However, the net charge on the molecule is -1.

The structure of a nitric acid molecule is as follows:

The physical properties of nitric acid are as follows:

• Molecular Weight: 63.01 g/mol
• Colour: Colourless
• Odour: Odourless
• pH: 3.01
• Density: 1.51 g/cm³
• Boiling Point: 83 °C
• Melting Point: -42°C

Nitric Acid has a variety of uses in different industries. Some of them are as follows:

• Nitric acid neutralizes with ammonium nitrate. This ammonium nitrate is an essential component in fertilizers and is widely used in its production. 

• Nitric acid is also commonly used for the production of anilines. Nitration is a process where nitric acid and sulfuric acid are combined to form nitronium ion. This nitronium ion reacts with various aromatic compounds to form different aniline derivatives.

• Nitric acid serves as a starting material for the formation of adipic acid.

• Nitric acid and its various forms serve as a rocket propellant. Red and white fuming acid with a mixture of sulfuric acid and HF inhibitor is used for this purpose.

• A polish of 10% nitric acid on old wood helps in providing a more new polished look.

• Nitric acid is also used as a cleaning agent in industries manufacturing electronics. It is also used alongside HCL to clean glass coverslips in microscopes and clean mirrors before silvering them.

• It is also used in the dairy industry to remove calcium and phosphorus compounds from dairy products. These compounds get settled during the purification process or due to the use of hard water during production.

• Nitric acid is also used as analytical reagents to find out traces of metals in different solutions. 

• Nitric acid, in its purest form, serves as a chemical to remove warts.

• It also helps in performing the colorimetric analysis to differentiate between heroin and morphine.

• Nitric acid helps in purifying carbon nanotubes and as a doping agent for semiconductors in electrochemistry.

• It is also an essential component in the production of various explosives like TNT.

Nitric Acid in class 11

In class 11, the chapter p-block elements discussed the various elements present in groups 13 to 18 of the periodic table. Their valence shell electronic configuration and basic reactions are also mentioned in this chapter.

Nitric Acid in class 12

In class 12, the chapter p-block elements discuss the properties, preparation, and uses of nitric acid and other nitrogen compounds. P-block elements carry a weightage of 8-10 marks in the exams. Hence, one or two questions on nitrogen compounds may be asked.

Q. Is Nitric Acid a strong oxidizing agent?

Q. How is Nitric Acid manufactured?

Q. What is the geometrical structure of Nitric Acid?

Q. Who discovered Nitric Acid?

Q. Can Nitric Acid cause burns?