Sulphuric Acid is an Acidic chemical compound with the formula H2SO4. It is widely used in the industries that is why it is called the king of chemicals. Its worldwide production clearly indicates its industrial strength. In the year 2004, its world production was about 180 million tonnes. It is also known as the oil of vitriol. It is an odourless, colourless and viscous liquid that is soluble in water. Preparation of sulphuric Acid generally involves highly exothermic processes.
The study of the oil of vitriol began in ancient times. It is believed that Muhammad ibn Zakariya al-Razi was the 1st alchemist of Iran who produced Sulphuric Acid. Then in the 17th century, German-Dutch Chemist Johann Glauber prepared Sulphuric Acid by sulphur with potassium nitrate. In 1736, Doctor Joshua Ward used this method for large-scale production of Sulphuric Acid, although it was an expensive method of production. After this many other methods of production of Sulphuric Acid were also discovered but they were not economically feasible.
Then in 1831, British vinegar merchant Peregrine Phillips patented the contact process, in which Sulphuric Acid is produced by using sulphur dioxide and oleum in presence of vanadium pentoxide as a catalyst. This method is more economically feasible than available all other methods and produces concentrated Sulphuric Acid. It is the current method of producing Sulphuric Acid on a large scale and the high concentration required for industrial processes.
Contact Process for Manufacturing of Sulphuric Acid
Industrially, Sulphuric Acid is produced by the reaction of water with sulphur trioxide, which is made by the chemical combination of sulphur dioxide and oxygen, either by the chamber process or the contact process.
Steps involved in the contact process of manufacturing Sulphuric Acid are listed below–
Preparation of sulphur dioxide
Oxidation of sulphur dioxide to prepare sulphur trioxide
Addition reaction of sulphur trioxide and Sulphuric Acid to give oleum
Dilution of oleum to produce concentrated Sulphuric Acid
Preparation of Sulphur Dioxide – In the 1st step sulphur is oxidised or burned to produce sulphur dioxide. The reaction is given below –
S(s) + O2(g) 🡪 SO2(g)
Oxidation of Sulphur Dioxide to Prepare Sulphur Trioxide – Sulphur dioxide is oxidised to sulphur trioxide in presence of vanadium pentoxide as a catalyst. It is an exothermic reaction that is reversible in nature. the reaction is given below –
2SO2(g) + O2(g) V2O5 🡪 2SO3(g)
Addition Reaction of Sulphur Trioxide and Sulfuric Acid to Give Oleum – Sulphur trioxide is absorbed into ~98% Sulphuric Acid to form oleum which is also known as fuming Sulphuric Acid. It is an additional reaction. The reaction is given below –
SO3(g) + H2SO4(I) 🡪 H2S2O7(I)
Dilution of Oleum to Produce Concentrated Sulfuric Acid – Oleum is diluted with water to form concentrated Sulphuric Acid. The reaction is given below –
H2S2O7(I) + H2O(I) 🡪 2H2SO4(I)
It should be noticed here that we used 1 mole of Sulphuric Acid as a reactant and produced 2 moles of Sulphuric Acid.
It is easy to remember the explanation of the Preparation of Sulfuric Acid with emphasis on the currently used preparation method – the Contact Process. If you are looking for NCERT Solutions of Chemistry Subject log on to the Vedantu website or Download the Vedantu learning app. By doing so you will not only get access to free PDFs of NCERT Solutions of Chemistry but other subjects as well.
FAQs on Preparation of Sulfuric Acid
1. What are the uses of sulphuric Acid?
Sulfuric Acid is one of the most important industrial chemicals. Some of its main uses are as follows:
One of the major uses of Sulphuric Acid is in the production of fertilisers like superphosphate of lime and ammonium sulphate.
It is widely used to manufacture chemicals like hydrochloric Acid, nitric Acid and sulphate salts, and in dyes and pigments.
In the production of cleaning agents like synthetic detergents.
It is used in explosives.
It is used in drain cleaners because of its reactive property.
It plays a role in wastewater processing and the processing of minerals.
In the paper industry, it is used to manufacture aluminium sulphate.
It is also used to produce drugs. For example, the chemotherapy drugs that work on damaging the cancerous cell DNA. It also finds its use in ointments to treat various skin infections.
It is used in petroleum refining to wash impurities out of gasoline and other refinery products.
It is used in processing metals. Sulfuric Acid is important in the process of cleaning iron and steel before plating them with tin or zinc.
It is used to make inorganic salts and Acids.
Rayon is made with Sulphuric Acid.
Sulfuric Acid serves as the electrolyte in lead-Acid storage batteries.
It is used for drying many wet gases which do not react with the Acid.
2. What is sulfonic acid?
Sulfonic acid or sulphonic acid is a class of organic acids containing sulfur. The formula for sulfonic acid is RSO3H. Sulfonic acid is one of the most important organosulfur compounds. These acids are widely used as catalysts in organic syntheses. Its other derivatives and salts are the basis of the manufacture of water-soluble dyes, detergents, sulfonamide pharmaceuticals and resins.
Aromatic sulfonic acids are used as intermediates or starting materials in synthesis, like phenols. Sulfonic acid groups can greatly enhance the water solubility of compounds, and the metal complexes of this compound are used as homogeneous catalysts for the synthesis of organic compounds in industries and laboratories.
3. What is the chamber process to produce sulfuric acid?
Also called the Lead-chamber Process, this method is used to produce sulfuric acid by oxidising sulphur dioxide with moist air, with the catalyst gaseous nitrogen oxides.
The reaction takes place in a series of large, box-shaped chambers made out of sheet lead.
This process has largely been replaced by the contact process in modern industrial production. This technique results in around 50-60 B grade acids.
In this process, we use wet SO2 in the presence of nitrogenous oxides, because of which it gets oxidised with the oxygen in the air, forming sulphur trioxide.
This reaction is expressed as:
2SO2 + O2 → 2SO3
Then sulphur trioxide is made to react with water to get H2SO4. This reaction is expressed as:
SO3 + H2O → H2SO4
4. What are the physical properties of sulphuric acid?
Physical Properties of Sulphuric Acid
It is dense and colourless.
It is an oily and corrosive liquid.
Its boiling point is 611 K. The hydrogen bonding is the reason for its high boiling point and thickness.
Pure sulfuric acid has a specific gravity of 1.830 at 298 K and at the temperature of 25 °C (or 77 °F).
It freezes at 10.37 °C (50.7 °F)
When heated, the pure acid partially decomposes into water and sulfur trioxide.
5. What are the chemical properties of sulphuric acid?
Here are some of its chemical properties:
It is a highly reactive and corrosive chemical that is soluble in water. It has very high oxidizing power and so it is a strong oxidizing agent.
Sulfuric acid is a strong dibasic acid. Also, it is diprotic and ionizes in two stages in the aqueous solution.
It has very low volatility. This is why it plays an important part in preparing more volatile acids.
Concentrated sulfuric acid is a very strong dehydrating agent.
It expels water from natural mixes like starches.
As it is a good oxidizing agent, it can oxidize both non-metals as well as metals.
It reacts vigorously with water, releasing quite a lot of heat. So one must never add water to H2SO4, and instead, add acid to water, with slow stirring.