At the beginning of the study of such a subject as chemistry, the most interesting thing is to conduct experiments, and if these experiments are also accompanied by a small spectacular explosion, then the enthusiasm is generally difficult to contain. At the word “explosion” various associations arise, and one of them is explosive gas. What is his formula, where is it used, and, of course, the safety rules when working with it are the main issues of the article.
Structure
In fact, the composition contains hydrogen mixed with oxygen. In a certain proportion of 1: 2 they form an explosive gas. Its formula will look like this: 2H 2 + O 2 .
The smallest spark with an energy of 14 mJ or heating to 510 ° C (the burning temperature of the match is more than 700 ° C) is enough to start a reaction between them, which is accompanied by the release of a large amount of energy and an explosion.
And the result of this reaction is ordinary water. It is not for nothing that the gas is called hydrogen, that is, it produces water. But it’s worth introducing, for example, spongy platinum, and the explosion will not happen, but the usual combustion process will go on.
Another name for the gas mixture is Brown gas, which got its name in honor of the inventor, who developed a car that works on the products of the decomposition of water by electrolysis. And the gas formula in chemistry looks like this: HHO.
Discovery story
The fact that during the chemical reaction between acids and some metals a gas is formed, which is very combustible, is mentioned in treatises of the 16th century. He was called "combustible air." But to collect it in its pure form, to study the properties and describe them only in the second half of the 18th century. So, the chemist A. Lavoisier, conducting experiments in 1784, concluded that gas is a simple substance consisting only of atoms of one kind.
And the famous chemist and physicist G. Cavendish experimentally managed to determine that oxygen + hydrogen gives water as a result of instant combustion. By the way, one of the laboratories of Cambridge was named in his honor precisely because he was able to determine the qualitative composition of water. The Latin name for hydrogen, Hydrogenium, comes from the two words "hydro" - water and "genoa" - birth, that is, it (as in the Russian version of the name of the element) describes its main property - to give birth to water.
Application
Where is it used?
Interest in such an alternative type of fuel as hydrogen is manifested more and more. But the first developer to introduce a car running on such fuel was Toyota. However, his FCHV SUV remained an exhibition specimen; they did not begin to be mass-produced. Interest in hydrogen engines has not disappeared, so many manufacturers continue to invest a lot of money to introduce such an engine.
Explosive gas, more precisely, hydrogen with oxygen supply, is used for welding and soldering metals in difficult conditions, such as tunnels and mines, manifolds and installation wells, when there is simply no place to place cylinders with hydrocarbons. The combustion temperature of the mixture is approximately 2235 ° C, and the combustion products are absolutely safe for human health. The hydrogen burner has found its application in jewelry and dental prosthetics, it is processed glass products, plates of expensive metals of different thicknesses and more.
The enemy of the miners
Sometimes the term "explosive gas" is mistakenly used in relation to methane. The ability of this hydrocarbon to accumulate in rock voids and when mixed with air becomes explosive, it is similar to a mixture of real gas, but this is where their similarity ends. The gas formula in chemistry is: CH 4.
The most dangerous concentration in the atmosphere of methane is 9.5%, but under different conditions it can vary from 5 to 16%. At a higher concentration, the gas will simply burn. An explosion can trigger both a spark and open fire. To control the methane concentration in the air, the miners took a canary with them, and they knew that as long as a little friend’s song was heard, they could work calmly. But once the bird was silent, it meant that the trouble was close.
At the beginning of the 19th century, Davy's miner's lamp replaced the singers, and today the control is carried out by an automatic system, but this does not make the work of the miners completely safe. Explosions sometimes happen now. Here it is such a terrible - "mine gas."
Bait for dishonest
How much happiness balloons filled with helium bring. There are few children who can resist the colorful miracle. And the holidays now can not do without helium balloons, which immediately soar up, it is worth letting the thread out of your hands for a second.
Today a helium cylinder costs decent money, and some negligent sellers decide to save. After all, not only helium, hydrogen can make a ball fly. Acetylene is also lighter than air. But is such a saving so safe for the customers themselves?
Recently, more and more news is heard about the explosions of balloons:
- May 2012 - Yerevan;
- October, 2017 - Kuzbass;
- October, 2017 - Kemerovo.
These are only three well-known cases, in one of them, namely at a rally in Yerevan, the balls were filled with hydrogen, which could go outside and accumulate in the air, mixing with oxygen. And we know that such a mixture in a certain proportion is called explosive gas. In this tragedy, people suffered.