Molecular and structural formula of methane
Molecular, structural and electronic formulaMethane are compiled on the basis of Butlerov's theory of the structure of organic substances. Before proceeding to write such formulas, we begin with a brief description of this hydrocarbon.
Features of methane
This substance is explosive, it is stillcalled "marsh" gas. The specific smell of this ultimate hydrocarbon is known to everyone. In the process of combustion from it does not remain chemical components that have a negative effect on the human body. It is methane that is an active participant in the formation of the greenhouse effect.
Physical properties
The first representative of the homologous series of alkaneswas discovered by scientists in the atmosphere of Titan and Mars. Given the fact that methane is associated with the existence of living organisms, a hypothesis has emerged about the existence of life on these planets. On Saturn, Jupiter, Neptune, Uranus, methane appeared as a product of chemical processing of substances of inorganic origin. On the surface of our planet its content is insignificant.
general characteristics
Methane has no color, it is lighter than air almost intwo times, poorly soluble in water. In the composition of natural gas, its amount reaches 98 percent. The oil passing gas contains from 30 to 90 percent of methane. To a greater extent, methane is of biological origin.
Ungulate herbivores and cows emit atprocessing in the stomachs of bacteria a fairly significant amount of methane. Among the important sources of the homologous series of alkanes, we distinguish swamps, termites, natural gas filtration, and the process of plant photosynthesis. If a trace of methane is found on the planet, we can talk about the existence of biological life on it.
Methods of obtaining
The detailed structural formula of methane isconfirmation of the fact that in its molecule only saturated single bonds formed by hybrid clouds. Among the laboratory options for the production of this hydrocarbon, we note the fusion of sodium acetate with solid alkali, as well as the interaction of aluminum carbide with water.
Methane burns with a bluish flame,This is about 39 MJ per cubic meter. Explosive mixtures this substance forms with air. The most dangerous is methane, which is released during the underground mining of mineral deposits in mines. There is a high risk of methane explosion at coal and briquetting enrichment plants, as well as in sorting facilities.
Physiological action
If the percentage of methane in the airis from 5 to 16 percent, with the ingress of oxygen, methane can ignite. In the case of a significant increase in the mixture of a given chemical, the probability of an explosion increases.
If in the air the concentration of this alkane is 43 percent, it is the cause of suffocation.
During the explosion, the propagation velocity is from 500 to 700 meters per second. After the methane contacts the heat source, the process of igniting the alkane occurs with some delay.
It is on this property that the production of explosion-proof electrical equipment and safety explosive components is based.
Since it is methane that is the most thermallystable saturated hydrocarbon, it has a wide application in the form of industrial and household fuel, and is also used as a valuable raw material for chemical synthesis. The structural formula of tri-ethyl-methane characterizes the structural features of representatives of this class of hydrocarbons.
In the process of its chemical interaction withchlorine under the influence of ultraviolet irradiation may form several products of the reaction. Depending on the amount of the starting material, chloromethane, chloroform, carbon tetrachloride can be obtained during replacement.
In the case of incomplete combustion of methane, soot is formed. In the case of catalytic oxidation, formaldehyde is formed. The final product of interaction with sulfur is carbon disulphide.
Features of the methane structure
What is its structural formula? Methane refers to the limiting hydrocarbons having the general formula CnH2n + 2. Consider the features of the formation of a molecule to explain how a structural formula is formed.
The methane consists of one carbon atom and four hydrogen atoms linked together by a covalent polar chemical bond. Let us explain on the basis of the structure of the carbon atom structural formulas.
Type of hybridization
The spatial structure of methane is characterized bytetrahedral structure. Since on the outer level of carbon there are four valence electrons, when the atom is heated, the electron passes from the second s-orbitals to p. As a result, at the last energy level, carbon has four unpaired ("free") electrons. The complete structural formula of methane is based on the formation of four hybrid clouds that are oriented in space at an angle of 109 degrees 28 minutes, forming the structure of the tetrahedron. Then overlapping vertices of hybrid clouds with non-hybrid clouds of hydrogen atoms occurs.
The complete and abbreviated structural formula of methane infully corresponds to Butlerov's theory. Between carbon and hydrogen, a simple (single) bond is formed, so the chemical reactions are not characterized by addition reactions.
Below is the final structural formula. Methane is the first representative of the saturated hydrocarbon class, it has the typical properties of the ultimate alkane. The structural and electronic formula of methane confirm the type of hybridization of the carbon atom in a given organic matter.
From school chemistry course
This class of hydrocarbons, representativewhich is "swamp gas", is studied in the 10th grade of the secondary school. For example, children are offered a task of the following character: "Write the structural formulas of methane". It is necessary to understand that for this substance, according to Butlerov's theory, only an expanded structural configuration can be written.
Its reduced formula will coincide withmolecular, should be written in the form of CH4. According to the new federal educational standards introduced in connection with the reorganization of Russian education, in the basic course of chemistry, all issues relating to the characteristics of classes of organic substances are reviewed in detail.
Industrial synthesis
Based on methane, industrialmethods of such an important chemical component as acetylene. The basis of thermal and electric cracking is precisely its structural formula. Methane forms a hydrocyanic acid during catalytic oxidation with ammonia.
Apply this organic substance forproduction of synthesis gas. When interacting with water vapor, a mixture of carbon monoxide and hydrogen is produced, which is the raw material for the production of limit monohydric alcohols, carbonyl compounds.
Of particular importance is the interaction with nitric acid, resulting in nitromethane.
Application in the form of automotive fuel
In connection with the lack of natural sourceshydrocarbons, as well as the impoverishment of the raw material base, the issue related to the search for new (alternative) sources for fuel production becomes particularly topical. One such option is biodiesel, which includes methane.
Given the difference in density between the petrolfuel and the first representative of the alkane class, there are certain features of its application as an energy source for automobile engines. In order to avoid the need to transport huge quantities of methane, the density is increased by compression (at a pressure of the order of 250 atmospheres). Store methane in a liquefied state in cylinders installed in cars.
Effects on the atmosphere
We have already spoken about the fact that methane rendersimpact on the greenhouse effect. If the degree of action of carbon monoxide (4) on the climate is taken conditionally for a unit, then the share of "swamp gas" is 23 units. Over the past two centuries, scientists have observed an increase in the quantitative content of methane in the Earth's atmosphere.
At the moment, the approximate number of CH4 is estimated at 1.8 parts per million. Despite the fact that this figure is 200 times less than the presence of carbon dioxide, there is a conversation between scientists about the possible risk of retention of heat radiated by the planet.
In connection with the excellent calorific value of the "swamp gas", it is used not only as a raw material in the implementation of chemical synthesis, but also as an energy source.
For example, on methane there are various gas boilers, columns, designed for individual heating systems in private houses and country cottages.
Such an autonomous heating option is very beneficialfor homeowners, is not associated with accidents that occur systematically on centralized heating systems. Thanks to the gas boiler operating on this type of fuel, 15-20 minutes is enough to completely heat a two-storey cottage.
Conclusion
Methane, structural and molecular formulaswhich was given above, is a natural source of energy. Due to the fact that in its composition there is only a carbon atom and hydrogen atoms, environmentalists recognize the ecological safety of this saturated hydrocarbon.
Under standard conditions (air temperature 20 degrees centigrade, pressure 101325 Pa), this substance is gaseous, non-toxic, insoluble in water.
In the case of a drop in air temperature to -161 degrees, methane is compressed, which is widely used in industry.
Methane has an impact on human health. It is not a poisonous substance, but is considered a suffocating gas. There are even limit values (MPC) for the content of a given chemical in the atmosphere.
For example, work in mines is allowed only in thosecases, when its amount does not exceed per cubic meter 300 milligrams. Analyzing the features of the structure of this organic matter, we can conclude that it is similar in chemical and physical properties to all other representatives of the saturated (limiting) hydrocarbon class.
We analyzed the structural formulas, the spatial structure of methane. The homologous series that begins the "swamp gas" has the general molecular formula CnH2n + 2.
