This group of substances include oil and methane,natural gas. Their variety is great. This, of course, about hydrocarbons. It is simultaneously one of the most common and most sought after human substances. What do they represent? It is worth remembering what chemistry in the 9th grade was telling.
Hydrocarbons
This class of substances combines a variety ofcompounds, most of which have long been successfully used for their own purposes by man. This is explained by the fact that carbon forms chemical bonds very easily, especially with hydrogen, therefore, such a diversity is observed. Without this, life would be impossible in the form in which we know it.
Hydrocarbons are substances consisting of two elements: carbon and hydrogen. Their molecules can be not only linear, but also branched, as well as form closed cycles.
Classification
Carbon forms four bonds, and hydrogen - 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 bonds, but double as well as triple bonds. According to this criterion, there are classes of hydrocarbons. In the first case, these substances are called limiting (or alkanes), and in the second - unsaturated or unsaturated (alkene and alkynes for two and three bonds, respectively).
Another classification providesconsideration of the molecule. In this case, there are aliphatic hydrocarbons, whose structure is linear, and carbocyclic, in the form of a closed circuit. The latter, in turn, are divided into alicyclic and aromatic.
In addition, hydrocarbons are often exposedpolymerization - the process of joining the same molecules to one another. The result is a completely new material, not like the base. An example would be polyethylene, obtained from just ethylene. This is only possible when it comes to unsaturated hydrocarbons.
Structures that also belong to the classunsaturated, can add new atoms other than hydrogen with their free radicals. In this case, other organic substances are obtained: alcohols, amines, ketones, ethers, proteins, etc. But these are already completely separate topics in chemistry.
Examples
Hydrocarbons are a huge variety of substances, even considering the classification. But it is worthwhile to briefly list the names of the compounds included in this numerous class.
- Limit 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. So called quite common types of gases.
- The class of alkenes (olefins) includes ethene (ethylene), propene (propylene), butene, pentene, hexene, etc.
- Alkynes include ethin (acetylene), propyne, butine, pentin, hexin, etc.
- By the way, double and triple bonds may not be single. In such a case, such structures belong to alkadiens and alkadins. But you shouldn't go too far.
- As for the hydrocarbons, whose structure is closed, they have their own names: cycloalkanes, cycloalkenes and cycloalkines.
- The names of the first: cyclopropane, cyclobutane, cyclopentane, cyclohexane, etc.
- The second class includes cyclopropene, cyclobutene, cyclopentene, cyclohexene, etc.
- Finally, cycloalkines, not found in nature.They tried to synthesize them for a very long time and long, and this was only possible at the beginning of the 20th century. Cycloalkine molecules consist of at least 8 carbon atoms. With fewer, the connection is simply unstable due to too much voltage.
- There are also arenas (aromatic hydrocarbons), the simplest and most common representative of which is benzene. Also this class includes naphthalene, furan, thiophene, indole, etc.
Properties
As mentioned above, hydrocarbons are a huge number of very different substances. Therefore, to talk about their common properties is somewhat strange, because there simply aren't any.
The same feature in all hydrocarbons canreckon unless 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 one.
There is one more similarity: all hydrocarbons have good flammability. At the same time, a lot of heat is generated, carbon dioxide and water are formed.
Natural sources
Как и другие полезные ископаемые, некоторые hydrocarbons are located in the form of deposits and reserves in the earth's crust. In particular, they make up most of the gas and oil. This is clearly seen in the processing of the latter: a huge amount of substances are released in the process, most of which relate specifically to hydrocarbons. Gas at all 80-97% usually consists of methane. In addition, methane is formed during the decomposition of organic waste and remains, so its receipt does not pose a serious problem.
Other sources of hydrocarbons are laboratories. Those substances that are not found in nature can be synthesized from other compounds using chemical reactions.
Using
Hydrocarbons play a huge role in modernlife of mankind. Oil and gas have become very valuable resources, because they serve as fuel and energy. But these are not the only ways to apply 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 different types of plastics, fabrics, etc. are made. Kerosene, solvents, paints and varnishes, paraffins, asphalt, tar, bitumen, and this does not include the main products of oil refining - gasoline and diesel fuel.
The value 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 in the simplest situations. It is extremely difficult to refuse to use them, even taking into account that oil and gas reserves will run out, as analysts predict. Already, humanity is actively seeking alternative sources of energy, but none of the options have so far shown the same efficiency and versatility as hydrocarbons.
