This group of substances includes oil and methane, natural gas. Their diversity is great. I'm talking, of course, about hydrocarbons. It is at the same time one of the most widespread and most demanded by mankind substances. What are they? It is worth remembering what chemistry was about in grade 9.
Hydrocarbons
This class of substances combines a variety of compounds, most of which have long been successfully used for their own purposes by humans. This is due to the fact that carbon forms chemical bonds very easily, especially with hydrogen, which is why there is such a variety. Without it, life as we know it would be impossible.
Hydrocarbons are substances consisting of two elements: carbon and hydrogen. Their molecules can be not only linear, but also branched, and also form closed cycles.
Classification
Carbon forms four bonds, and hydrogen forms one. But this does not mean that their ratio is always 1 to 4. The fact is that between carbon atoms there can be not only single, but also double, as well as triple bonds. According to this criterion, classes are distinguishedhydrocarbons. In the first case, these substances are called saturated (or alkanes), and in the second - unsaturated or unsaturated (alkenes and alkynes for two and three bonds, respectively).
Another classification involves the consideration of the molecule. In this case, aliphatic hydrocarbons are distinguished, the structure of which is linear, and carbocyclic, in the form of a closed chain. The latter, in turn, are divided into alicyclic and aromatic.
Besides this, hydrocarbons often undergo polymerization - the process of attaching identical molecules to one another. The result is a completely new material, not similar to the base. An example is polyethylene, which is made from just ethylene. This is only possible when it comes to unsaturated hydrocarbons.
Structures, which also belong to the class of unsaturated ones, can also add new atoms other than hydrogen with the help of their free radicals. In this case, other organic substances are obtained: alcohols, amines, ketones, ethers, proteins, etc. But these are completely separate topics in chemistry.
Examples
Hydrocarbons are a huge variety of substances, even taking into account the classification. But still, it is worth briefly listing the names of the compounds included in this numerous class.
- Ultimate hydrocarbons are methane, ethane, propane, butane, pentane, hexane, heptane, etc. The first and third names are probably familiar even to those who are not particularly friendly with chemistry. Soquite common types of gases are called.
- The class of alkenes (olefins) includes ethene (ethylene), propene (propylene), butene, pentene, hexene, etc.
- Alkynes include ethyne (acetylene), propyne, butyne, pentyn, hexine, etc.
- By the way, double and triple bonds may not be single. In this case, such structures belong to alkadienes and alkadiines. But don't go too deep.
- As for hydrocarbons, the structure of which is closed, they have their own names: cycloalkanes, cycloalkenes and cycloalkynes.
- Names of the first: cyclopropane, cyclobutane, cyclopentane, cyclohexane, etc.
- The second class includes cyclopropene, cyclobutene, cyclopentene, cyclohexene, etc.
- Finally, cycloalkynes that do not occur in nature. They tried to synthesize them for a very long time and for a long time, and this was only possible at the beginning of the 20th century. Cycloalkyne molecules consist of at least 8 carbon atoms. With less, the connection is simply unstable due to too much voltage.
- There are also arenes (aromatic hydrocarbons), the simplest and most common representative of which is benzene. Also in this class are naphthalene, furan, thiophene, indole, etc.
Properties
As mentioned above, hydrocarbons are a huge amount of a wide variety of substances. Therefore, it is somewhat strange to talk about their common properties, because there simply are none.
The only thing that can be considered the same feature for all hydrocarbons is the composition. And also the fact that at the beginning of each row,as the number of carbon atoms increases, there is a transition from a gaseous and liquid form to a solid.
There is another similarity: all hydrocarbons have good flammability. In this case, a lot of heat is released, carbon dioxide and water are formed.
Natural Springs
Like other minerals, some hydrocarbons are located in the form of deposits and reserves in the earth's crust. In particular, they make up the majority of gas and oil. This is clearly seen during the processing of the latter: a huge amount of substances are released in the process, most of which relate specifically to hydrocarbons. Gas and at all for 80-97% usually consists of methane. In addition, methane is produced by the decomposition of organic waste and remains, so its production is not a serious problem.
Other sources of hydrocarbons - laboratories. Those substances that do not occur in nature can be synthesized from other compounds using chemical reactions.
Use
Hydrocarbons play a huge role in the modern life of mankind. Oil and gas have become very valuable resources because they serve as fuel and energy carriers. But these are not the only ways to use compounds from this class. Hydrocarbons are literally everything that surrounds people in everyday life. With the help of polymerization, it was possible to obtain new materials from which various types of plastics, fabrics, etc. are made. Kerosene, solvents, paints and varnishes, paraffins, asph alt, tar, bitumen, and this is not counting the main productsoil refining - gasoline and diesel fuel.
The significance of these substances is enormous. Both unsaturated and saturated hydrocarbons are hundreds and thousands of things that every person is used to and cannot do without them in the simplest situations. It is extremely difficult to refuse their use, even taking into account the fact that oil and gas reserves will run out, as analysts predict. Humanity is already actively searching for alternative energy sources, but none of the options has yet shown the same efficiency and versatility as hydrocarbons.
