Production of sulfuric acid

Sulfuric acid was formerly called the “Sulfur ink”, a very strong acid that dissolves with each percentage of water, and its chemical formula is H2SO4.


Ph (pH) of this acid is 0/5 (5 tenths).

Sulfuric acid was first discovered by Jaber Ibn Hayan. He obtained this acid by distillation of ferric sulfate minerals (iron sulfate-7 in FeSO 4, 7H₂O) and copper (II) sulfate.

Sulfuric acid is used in detergent, paint and so on.

Physical Properties:
It has molecules with polar torque that can make hydrogen bond together. So, sulfuric acid is a liquid with a boiling point and also a viscous liquid (high in high cost). The same molecular conditions make sulfuric acid well dissolved in water and produce different acid solutions.

Molecular structure and acidity:
It consists of molecules including a sulfur atom, four oxygen atoms, and two hydrogen atoms. Because the hydrogen is attached to the oxygen atom, it carries a positive charge and is able to act as acidic hydrogen. With the loss of the first hydrogen, anion is produced by hydrogen sulfate, which is highly stable due to resonance structures; therefore, the first separation of sulfuric acid is performed in full:

H2SO4 + H2O → HSO4- + H3O + (1

For the second step, hydrogen must leave hydrogen in the form of cation, anion, hydrogen sulfate, which is not so easy; therefore, the separation of the second acid in sulfuric acid is not complete and is an equilibrium reaction:

HSO4 + H2O + H3O + + SO42- (2


Sulfuric acid production:

Proximity Process:

almas shimi mofid plant is used to produce sulfuric acid in this way.

Sulfuric acid is one of the most important industrial chemicals produced by the proximity process. In the first step, sulfur in the vicinity of oxygen, oxidized and sulfur dioxide is obtained:

S (s) + O2 (g) → SO2 (g) (1

In the next step, sulfur dioxide is oxidized in the vicinity of a catalyst and, in reaction with the additional oxygen, oxidizes to SO3:

SO2 (g) + O2 (g) → SO3 (g) (2

This reaction is hot, and its entropy decreases because the entropy agent is unfavorable; it has an unfavorable thermodynamic effect, so it is reversible.

The reaction is very slow at the normal temperature; therefore, in industrial process, it is used at higher temperatures (400 ° C to 700 ° C) and from a catalyst (such as vanadium pentoxide V2O5 or platinum sponge, which is today used less often). . From the reaction of sulfur trioxide with water, a solution of sulfuric acid is formed:

SO3 (g) + H2O (1) → H2SO4 (aq) (3

By repeating the above steps and blowing sulfur trioxide into a solution of sulfuric acid, sulfuric acid (H2S2O7) is formed:

H2SO4 (1) + SO3 (g) → H2S2O7 (l) (4

Then, by adding water to sulfuric acid, prepare a solution of sulfuric acid:

H2S2O7 (1) + H2O (1) → 2H2SO4 (1) (5

Control of this method, in which pyrosulfuric acid is formed, is easier than the direct reaction of sulfur trioxide with water, so this reaction is used to produce sulfuric acid with a specified percentage and concentration desired.

Other methods
1- Sulfuric acid can be obtained from the reaction of sulfur dioxide with hydrogen peroxide (oxygenated water).

(g) + H2O2 (1) → H2SO4 (1) SO2
2. Another method for producing sulfuric acid in the laboratory is by using electrolysis of copper (ll) solution, the cathode must be of a conductive metal, such as copper and anode, which should be of platinum or charcoal to not react with the solution.