{"id":7570,"date":"2018-04-24T15:31:20","date_gmt":"2018-04-24T15:31:20","guid":{"rendered":"https:\/\/www.experimentoscientificos.es\/?page_id=7570"},"modified":"2018-11-26T17:14:19","modified_gmt":"2018-11-26T17:14:19","slug":"hidrogeno","status":"publish","type":"page","link":"https:\/\/www.experimentoscientificos.es\/en\/hidrogeno\/","title":{"rendered":"Hydrogen"},"content":{"rendered":"

The hydrogen<\/strong> is the first chemical element in the periodic table<\/a>. Hydrogen is the chemical element with the atomic number 1, represented by the symbol H<\/strong>. It has only one proton in the nucleus and one electron spinning around it.<\/p>\n

Hydrogen is the most abundant chemical element, making up about 75 % of the visible matter in the universe.<\/sup>For example, stars are mainly composed of hydrogen in the plasma state. On Earth, it is part of water molecules, all acids and hydrocarbons. However, as an isolated element it is relatively rare and is produced from hydrocarbons. Most elemental hydrogen is available where and when it is needed.<\/p>\n

PHYSICO-CHEMICAL PROPERTIES OF HYDROGEN<\/h2>\n

Atomic mass:<\/strong> 1,00794 u \u00b1 0,00001 u
\nDensity<\/a>:<\/strong> 0.0899 kg\/m3
\nAtomic radius (calc)<\/strong>: 53 pm (Bohr radius)
\nGroup, period, block:<\/strong> 1, 1, s
\nName, symbol, number:<\/strong> Hydrogen, H, 1
\nOrdinary status:<\/strong> Gas
\nMelting point<\/a>:<\/strong>\u00a014,025 K (-259 \u00b0C)
\nBoiling point<\/a>:\u00a0<\/strong>20,268 K (-253 \u00b0C)
\nSpecific heat<\/strong><\/a>: 1,4304-104<\/sup>\u00a0J\/(K-kg)<\/p>\n

n\u00baCAS:\u00a0<\/strong>1333-74-0
\nEINECS no:\u00a0<\/strong>215-605-7<\/p>\n

ATOMIC STRUCTURE OF HYDROGEN AND ISOTOPES<\/h2>\n
\u00a0The atomic structure of hydrogen is as follows a proton in the nucleus and an electron spinning around the nucleus<\/strong>its common oxidation state is therefore 1+.<\/div>\n
\n

\"Hidr\u00f3geno\"The atom<\/a> The second isotope is called deuterium and has a nucleus consisting of one proton and one neutron. It is a stable isotope but not very abundant in nature (only 0.015% of hydrogen atoms are deuterium). The third isotope, called tritium, has a nucleus consisting of two neutrons and one proton. Due to the imbalance between protons and neutrons, this atom is unstable and disintegrates radioactively to form a helium atom:<\/p>\n

\"hidrogeno_helio\"<\/p><\/blockquote>\n<\/div>\n

HYDROGEN IN NATURE<\/h2>\n

Hydrogen is the most abundant chemical element in nature, making up approximately 75% of the visible matter in the universe. Both stars and the sun are composed mainly of hydrogen in the plasma state. Elemental hydrogen is relatively rare on Earth; it is obtained in situ when needed, usually from hydrocarbons.\u00a0<\/sup><\/p>\n

Hydrogen forms compounds with most of the\u00a0chemical elements.\u00a0<\/a>It is present in water (H2O) and in most organic compounds. It plays a particularly important role in the chemistry of\u00a0acid-base reactions<\/a>\u00a0and in the pH<\/a> of solutions. Acid-base reactions involving an exchange of H+ ions between molecules. The study of the energy and bonding of the hydrogen atom has been fundamental to the point of having played a major role in the development of the\u00a0quantum mechanics<\/a>.<\/p>\n

FLAMMABILITY<\/h2>\n

H2 gas (dihydrogen<\/sup>) is highly flammable and burns at concentrations of 4 % or more H2<\/sub>\u00a0in the air.<\/sup>The enthalpy of combustion of hydrogen is -286 kJ\/mol; it burns according to the following balanced equation.<\/p>\n

\n
2 H2<\/sub>(g) + O2<\/sub>(g) \u2192 2 H2<\/sub>O(l) + 572 kJ (286 kJ\/mol)<\/strong><\/sup><\/dd>\n<\/dl>\n

HYDROGEN COMPOUNDS AND APPLICATIONS<\/h2>\n

ORGANIC COMPOUNDS<\/h3>\n

Hydrogen forms an enormous variety of compounds with carbon. Due to their presence in living things, these compounds are called organic compounds<\/strong>Its properties are part of organic chemistry.<\/p>\n

The\u00a0carbon-hydrogen bonding<\/strong>, CH<\/strong>is what gives these compounds many of their main characteristics. Classes of compounds with only C-H carbon-hydrogen bonds and C-C carbon-carbon bonds are called hydrocarbons. The C-H bond is difficult to break. The type of reactions in which these bonds are destroyed require an energy input to initiate the reaction, such as: Combustions, substitutions, acid-base reactions.<\/p>\n

INORGANIC COMPOUNDS<\/h3>\n

Some examples of compounds covalent<\/a> The most important hydrogen-containing substances are: ammonia (NH3<\/sub>), hydrazine (N2<\/sub>H4<\/sub>),\u00a0water<\/a>\u00a0(H2<\/sub>O), hydrogen peroxide (H2<\/sub>O2<\/sub>), hydrogen sulphide (H2<\/sub>S), etc.<\/p>\n

HYDRAULES<\/h3>\n

Any hydrogen compound is often referred to as a hydride, but this is very inaccurate. The term hydride<\/strong>\u00a0 implies that the hydrogen atom has acquired a negative partial charge ( H–<\/sup><\/strong>).<\/p>\n

ACIDS<\/h3>\n

The oxidation of H2<\/sub>\u00a0originates the proton, H+<\/sup>. An isolated proton H+<\/sup>\u00a0cannot exist in solution because of its strong tendency to bind to atoms or molecules. To avoid the convenient, but uncertain, idea of the isolated proton in solution, in aqueous acidic solutions the presence of the hydronium ion (H3<\/sub>O+<\/sup>). Some of the better known acids are hydrochloric acid<\/a>sulphuric acid,...<\/p>\n

HYDROGEN ENERGY<\/h2>\n

Hydrogen is not a source of energy<\/strong>Only deuterium or tritium fusion is under development (but far from being a reality).<\/p>\n

The sun's energy comes from the nuclear fusion of hydrogen, but this process is difficult to achieve in a controllable way on Earth.\u00a0<\/sup>Elemental hydrogen from solar, biological, or electrical sources requires more energy to create what is obtained by burning it, so in these cases, hydrogen serves as an energy carrier, like a battery. It can be obtained from fossil sources (such as methane), but these sources are unsustainable.<\/sup><\/p>\n

 <\/p>\n

H2 GAS APPLICATIONS<\/h2>\n