In this article we will consider obtaining hydrogen sulfide from sulfur. Let us examine in more detail the physical and chemical properties of this substance.
Structure
In order to analyze the main production of hydrogen sulfide, it is necessary to find out the features of its structure. The composition of this substance contains one sulfur atom and two hydrogen. They are non-metals; therefore, covalent polar bonds form between the elements . In hydrogen sulfide, an angular structure. An angle of 92 degrees forms between sulfur and hydrogen, which is slightly less than in water.
Physical properties
The smell of hydrogen sulfide, reminiscent of rotten eggs, is familiar to everyone. Under normal conditions, this substance is in a gaseous state. It has no color, is poorly soluble in water, poisonous. On average, 2.4 volumes of hydrogen sulfide will dissolve in water at 20 degrees Celsius. Sulfuric water revealed insignificant acidic properties, the dissociation of the substance proceeds stepwise. Poisonous hydrogen sulfide is dangerous even in small doses. A content of about 0.1 percent hydrogen sulfide in the air leads to paralysis of the respiratory center with loss of consciousness. For example, the legendary natural scientist Pliny the Elder died in the 79th century BC precisely from hydrogen sulfide, which was formed during the eruption of Vesuvius.
The reason for the poisoning effect of hydrogen sulfide is its chemical interaction with hemoglobin. The iron contained in this protein forms sulfide with hydrogen sulfide.
The maximum permissible concentration in the air of hydrogen sulfide is considered to be 0.01 mg / l. As an antidote, inhalation of pure oxygen or air, which contains a small amount of chlorine, is used.
Working with hydrogen sulfide requires compliance with certain safety rules. All experiments related to this gaseous substance are carried out in sealed devices and fume hoods.
Methods for producing hydrogen sulfide
What is the production of hydrogen sulfide in the laboratory? The most common option is the interaction of hydrogen with sulfur. This chemical reaction refers to the compound, carried out in a fume hood.
In addition, the production of hydrogen sulfide is possible with the exchange between solid iron sulfide (2) and a solution of sulfuric or hydrochloric acid. To get this result, in a test tube it is enough to take several pieces of sulfide, not exceeding the size of a pea. Next, an acid solution is added to the test tube (up to half the volume), closed with a gas tube. The device is placed under the hood, the tube is heated. Chemical interaction is accompanied by the release of gas bubbles. This production of hydrogen sulfide allows you to create the amount of substance sufficient to consider its chemical properties.
What other ways are there? In the laboratory, hydrogen sulfide can be produced by reacting metallic iron (under the hood) with crystalline sulfur, followed by the interaction of sulfide with sulfuric acid.
Chemical properties
Hydrogen sulfide interacts with atmospheric oxygen, it burns with a bluish color. In the case of complete combustion, the reaction products are sulfur oxide (4) and water. Given that the furnace gas is an acid oxide, in the solution it forms a weak sulfuric acid, which turns the blue litmus paper red.
In the case of insufficient hydrogen sulfide, crystalline sulfur is formed. This process is considered an industrial method of obtaining pure sulfur from hydrogen sulfide.
This chemical also has excellent reducing ability. They appear, for example, in the interaction with salts, halogens. In order to carry out a similar reaction under laboratory conditions, a solution of hydrogen sulfide is poured into test tubes with chlorine and bromine, discoloration is observed. As a reaction product, crystalline sulfur formation is observed.
During the chemical reaction of hydrogen sulfide with water, the formation of the hydroxonium cation H3O + occurs.
Hydrogen sulfide is able to form two types of compounds: sulfides (middle salts) and hydrosulfides (acid salts).
In alkali and alkaline earth metals, sulfides are colorless compounds. In heavy metals (copper, nickel, lead) they are black. Manganese sulfide is pink. Many salts are not soluble in water.
A qualitative reaction to sulfides is considered interaction with a solution of copper sulfate (2). The product of this interaction will be the precipitation of a black precipitate of copper sulfide (2).
Conclusion
In nature, this substance is found in mineral springs, volcanic gases. This compound is a product of rotting animals and plant organisms, it is distinguished by the characteristic smell of hydrogen sulfide. Natural sulfides are found in rare metals; in metallurgy, corresponding elements are obtained from them. It is important to remember that hydrogen sulfide is a strong toxic substance.