Chemical formula of sulfuric acid. Sulfuric acid: chemical properties, preparation
H2SO3, weak dibasic acid. In a free form it is not allocated, exists in water solutions. Sulfuric acid sulfites ... Big Encyclopedic Dictionary
Sulfuric acid - (H2SO3) weak dibasic acid. Exists only in aqueous solutions. Salts S. to. Sulfites. Applied in the pulp paper and food industry. See also Acids and anhydrides ... Russian encyclopedia on labor protection
sulfuric acid - - [A.S. Goldberg. English Russian energy dictionary. 2006] Topics of energy in general EN sulfurous acid ... Technical Translator's Guide
H2SO3, weak dibasic acid. In a free form it is not allocated, exists in water solutions. Sulfuric acid sulfites. * * * Sulfuric acid, sulfuric acid, H2SO3, weak dibasic acid. Free is not selected, ... ... encyclopedic Dictionary
sulfuric acid - sulfito rūgštis statusas T sritis chemija formulė H₂SO₃ atitikmenys: angl. sulfurous acid rus. sulfuric acid ryšiai: sinonimas - vandenilio trioksosulfatas (2–) ... Chemijos terminų aiškinamasis žodynas
H2SO3, weak dibasic acid, corresponding to the degree of sulfur oxidation +4. Known only in dilute aqueous solutions. The dissociation constants: K1 = 1.6 · 10 2, K2 = 1.0 · 10 7 (18 ° C). It gives two rows of salts: normal Sulfites and sour ... ... Great Soviet Encyclopedia
H2SO3, weak dibasic acid. In the free form is not highlighted, it exists in the waters. p rah. Salts S. k. Sulfites ... Natural science. encyclopedic Dictionary
See Sulfur ... Encyclopedic dictionary of FA Brockhaus and I.A. Efrona
Sulfur dioxide (dioxide) is formed by burning sulfur in air or oxygen. It is also obtained by calcining in the air ("burning") sulphides of metals, for example, iron pyrites:
According to this reaction, sulfur dioxide is usually obtained in industry (for other industrial methods of obtaining cm, 9 § 131).
Sulfur dioxide is a colorless gas ("sulfur dioxide") with a sharp eapach of hot sulfur. It condenses quite easily into a colorless liquid boiling at. When the liquid evaporates, there is a strong decrease in temperature (before).
Sulfur dioxide is highly soluble in water (about 40 volumes in 1 volume of water at); at the same time, the reaction with water partially takes place and sulfurous acid is formed:
Thus, sulfur dioxide is sulfuric acid anhydride. When heated, the solubility decreases and the equilibrium shifts to the left; gradually all sulfur dioxide is released from the solution again.
The molecule is built similarly to the ozone molecule. The nuclei of its constituent atoms form an isosceles triangle:
Here, the sulfur atom, like the central oxygen atom in the ozone molecule, is in the α-hybridization state and the angle is close to. Oriented perpendicularly to the plane of the molecule, the orbital of the sulfur atom does not participate in the hybridization. Due to this orbitals and, similarly oriented, orbitals of oxygen atoms, a three-center bond is formed; the electron pair carrying it belongs to all three atoms of the molecule.
Sulfur dioxide is used to produce sulfuric acid, and also (in much smaller quantities) for bleaching straw, wool, silk and as a disinfectant (for the destruction of mold fungi in basements, cellars, wine barrels, fermentation tanks).
Sulfuric acid is a very fragile compound. It is known only in aqueous solutions. When trying to isolate sulfurous acid, it disintegrates into water. For example, when concentrated sulfuric acid acts on sodium sulfite, sulfur dioxide is released instead of sulfurous acid:
Sulfuric acid solution must be protected from air, otherwise it, absorbing oxygen from the air, slowly oxidizes to sulfuric acid:
Sulfuric acid is a good reducing agent. For example, free halogens are restored by it to hydrogen halides:
However, when interacting with strong reducing agents, sulfuric acid may play the role of an oxidizing agent. So, its reaction with hydrogen sulfide mainly proceeds according to the equation:
Being dibasic, sulfurous acid forms two rows of salts. Its middle salts are called sulfites, acid salts - hydrosulfites.
Like acid, sulfites and hydrosulfites are reducing agents. When they are oxidized, salts of sulfuric acid are obtained.
Sulphites of the most active metals during calcination decompose with the formation of sulphides and sulphates (self-oxidation reaction - self-reduction):
Potassium and sodium sulfites are used for bleaching some materials in the textile industry for dyeing fabrics, in photography. The solution (this salt exists only in solution) is used to process wood into the so-called sulfite pulp, from which paper is then obtained.
Sulfurous acid is able to react with oxygen. This forms sulfuric acid. This reaction takes a very long time and is possible only if the storage rules are violated. Sulfuric acid has both oxidizing and reducing properties. With its help you can get halogen acids. An aqueous solution when reacting with chlorine forms hydrochloric and sulfuric acid.
When reacting with strong reducing agents, sulfurous acid plays the role of an oxidizing agent. One of these substances is hydrogen sulfide, a gas with a very unpleasant odor. Interacting with an aqueous solution of sulfuric acid, it forms sulfur and water. Sulfuric acid salts also have reducing properties. They are divided into sulfites and hydrosulfites. Oxidation reactions of these salts produce sulfuric acid.
Sulfuric acid production
Sulfuric acid is formed only by the interaction of sulfur dioxide and water. Need to get sour gas. This can be done with copper and sulfuric acid. Gently pour the concentrated sulfuric acid into the tube and throw a piece of copper into it. Heat the tube with a spirit lamp.
As a result of heating, copper sulphate (copper sulphate), water and sulfur dioxide is formed, which with the help of a special tube must be brought to the cone with clear water. In this way, sulfuric acid can be obtained.
Remember that sulfur dioxide is harmful to humans. It causes airway damage, loss of appetite and headache. Prolonged inhalation may cause fainting. When working with him need caution.
Use of sulfuric acid
Sulfuric acid has antiseptic properties. It is used in the disinfection of surfaces, grain fermentation. It can be used to bleach some substances that decompose when they react with strong oxidants (for example, chlorine). Such substances include wool, silk, paper and some others. Its antibacterial properties are used to prevent the fermentation of wine in barrels. Thus, a noble drink can be stored for a very long time, acquiring a noble taste and unique aroma.
Sulfuric acid is used in the manufacture of paper. The addition of this acid is included in the technology of sulphite pulp production. Then it is treated with a solution of calcium hydrosulfite to bind the fibers together.