Physical properties of hydrogen.

H Hydrogen - a chemical element, one of the most common in our universe.The mass of hydrogen as an element in the composition of matter is 75% of the total content of atoms of another type.It is part of the overriding and vital connection to the planet - water.A distinctive feature of hydrogen is also a fact that it is the first element in the periodic table of chemical elements of Mendeleev.

discovery and investigation

first mention of hydrogen in the writings of Paracelsus date back to the sixteenth century.But his selection from a gas mixture of air and flammable properties of the study were made in the seventeenth century scientist Lemaire.Hydrogen thoroughly studied English chemist, physicist and scientist Henry Cavendish, which is empirically proven that the mass of hydrogen in the lowest compared with other gases.In later stages of the development of science, many scientists have worked with him, such as Lavoisier, who called it "gives birth to water."

features on the situation PSKHE

element that opens the periodic table Mendeleev - is hydrogen.Physical and chemical properties of atoms exhibit a certain duality, as Hydrogen simultaneously belong to the first group, the main subgroups if it behaves as a metal and gives only one electron in the process of a chemical reaction, and the seventh - in the case of complete filling of the valence shell, ie receptionnegative particles, which characterizes it as similar to a halogen.

features of the electronic structure element

properties of the hydrogen atom, complex substances, to which it is part, and the most simple material H2 is primarily determined by the electron configuration of Hydrogen.The particle has an electron with Z = (-1), which rotates in its orbit around the nucleus containing one proton with a unit mass and a positive charge (+1).Its electron configuration is recorded as 1s1, which means the presence of a negative particle in the very first and the only one for the s-orbital of Hydrogen.

If divorced or recoil electron and an atom of the element is the property that links him with the metal cation is obtained.In fact, the hydrogen ion - this positive elementary particles.Hydrogen is therefore devoid of an electron is called simply a proton.Physical properties

Described briefly hydrogen physical properties, it is colorless, sparingly soluble gas with a relative atomic mass of 2, 14.5 times lighter than air, with a temperature of liquefaction component -252.8 degrees Celsius.

on experience can be easily seen that H2 easiest.It's enough to fill three balls of various substances - hydrogen, carbon dioxide, ordinary air - and at the same time let them out of hand.The fastest to reach the earth, which is filled with CO2, after the fall pressurized air mixture containing H2 and all will rise to the ceiling.

small weight and size of the particles of hydrogen substantiate its ability to penetrate through various substances.For example, the same ball in this easy to make in a few days he had blown away, just as the gas will pass through the rubber.Also, hydrogen can accumulate in the structure of certain metals (palladium or platinum) and at higher temperatures to evaporate from it.

property is poorly soluble hydrogen used in the laboratory to highlight water displacement method.The physical properties of hydrogen (table shown below, contains the basic parameters) define its scope and methods of preparation.

isotopic composition of

Like many other representatives of the periodic table of chemical elements, Hydrogen has several natural isotopes, ie atoms with the same number of protonsin the nucleus, but a different number of neutrons - particles with zero and unit charge mass.Examples of atoms having similar property - oxygen, carbon, chlorine, bromine and the like, including radioactive.

physical properties of hydrogen 1H, the most widespread of the representatives of this group are significantly different from the same characteristics of its counterparts.In particular, the different features of substances in which they are incorporated.So, there is a normal and deuterated water containing in the structure instead of a hydrogen atom with a single proton, deuterium, 2H - its isotope with two elementary particles: positive and uncharged.This isotope is two times heavier than usual of Hydrogen, which explains the fundamental difference in the properties of the compounds which they form.The nature of the deuterium found 3,200 times rarer than hydrogen.A third representative - tritium 3H, in the kernel it has two neutrons and one proton.

Methods for preparing and isolating

laboratory and industrial methods of hydrogen production are quite different.Thus, small amounts of gas is produced mainly by reactions involving minerals, and large-scale production of increasingly using organic synthesis.

The lab used the following chemical reactions:

1. reaction of alkali and alkaline earth metals with water to form alkali and the desired gas.
2. electrolysis of an aqueous solution of electrolyte, the anode stands H2 ↑, and the cathode - oxygen.
3. decomposition of water, alkali metal hydrides, alkali and the products are, respectively, gas H2 ↑.
4. reaction with dilute acids to form metal salts and H2 ↑.
5. action of alkali on silicon, aluminum and zinc and promotes the release of hydrogen in parallel to form complex salts.

in the interests of the gas industry is obtained by methods such as:

1. thermal decomposition of methane in the presence of a catalyst to make up his simple substances (350 degrees reaches the value of this indicator, temperature) - hydrogen H2 and carbon ↑ S.
2. transmittance vaporwater through the coke at 1000 ° C to form carbon dioxide CO2 and H2 ↑ (the most common method).
3. conversion of methane gas on the nickel catalyst at temperatures up to 800 degrees.
4. Hydrogen is a byproduct during the electrolysis of aqueous solutions of sodium or potassium chloride.

Chemical interaction: general

physical properties of hydrogen largely explain his conduct in responding to this or that connection.Valency of Hydrogen is 1 as it is located in the periodic table in the first group, and exhibits a different oxidation state.All compounds except hydrides, hydrogen sd = (1+), in molecules such as CN, XH2, HN3 - (1).

molecule of hydrogen gas, formed by providing generalized electron pair consists of two atoms and rather stable energetically, it is therefore under normal conditions and more inert reacting a change in normal conditions.Depending on the degree of oxidation of the hydrogen in the structure of other substances, it can serve both as an oxidant and reductant.

Substances which reacts to form hydrogen

Elemental interactions to form the complex substance (often at elevated temperatures):

1. alkali and alkaline earth metal + = hydrogen hydride.
2. Halogen + H2 = hydrogen halide.
3. Sulfur + = hydrogen sulfide.
4. oxygen = water + H2.
5. Carbon + Hydrogen = methane.
6. Nitrogen + H2 = ammonia.

interaction with complex substances:

1. Getting synthesis gas from carbon monoxide and hydrogen.
2. Recovery of metals from their oxides by H2.
3. hydrogen saturation of unsaturated aliphatic hydrocarbons.

hydrogen bond

physical properties of hydrogen are such that allow it, being in connection with an electronegative element, to form a special type of connection with the same atoms from neighboring molecules with unshared electron pairs (eg, oxygen, nitrogen and fluorine).The clearest example of where better to see this phenomenon - it is water.It can be said stitched hydrogen bonds that are weaker than covalent or ionic but due to the fact that many of them have a significant influence on the properties of substances.In fact, hydrogen bond - is the electrostatic interaction, that binds water molecules into dimers and polymers, proving its high boiling point.

Hydrogen composed of mineral compounds

The composition of inorganic acids include proton - atom cation such as hydrogen.Substance acid residue which has a degree of oxidation greater than (-1) is said polybasic compound.At present there are several hydrogen atoms that does dissociate in aqueous solutions multistage.Each subsequent proton acid residue comes off harder.By quantitative hydrogen content in the medium is determined by its acidity.

contain hydrogen and hydroxyl bases.They are connected to the hydrogen atom of oxygen, resulting in oxidation of the residue alkali always is equal to (-1).On the content of hydroxyl groups in the environment is determined by its basic.

Application human

cylinders substance, as well as containers and other liquefied gases such as oxygen, have a particular appearance.They painted a darkish-green color with bright red word "Hydrogen".Gas is pumped into the tank under pressure of about 150 atmospheres.Physical properties of hydrogen, in particular ease of gaseous aggregate state and is used for filling them with a mixture of helium balloons, balloons, etc.

Hydrogen, physical and chemical properties which people have learned to use many years ago, at the moment involved in many industries.Its main mass goes to the production of ammonia.Also hydrogen participates in the production of metals (hafnium, germanium, gallium, silicon, molybdenum, tungsten, zirconium, and others) of the oxides, the reaction acting as a reductant, and a salt of hydrocyanic acid, methyl alcohol, and synthetic liquid fuels.The food industry uses it to convert vegetable oils into solid fats.

determine the chemical properties and the use of hydrogen in various hydrogenation processes and hydrogenation of fats, coal, hydrocarbons, oil and fuel oil.With it produces precious stones, incandescent, spend forging and welding of metal products under the influence of oxygen-hydrogen flame.