Senin, 10 Oktober 2011

HYDROGEN

Understanding.
Hydrogen is a chemical element in the periodic table that has the symbol H and atomic number 1. At standard temperature and pressure, hydrogen is colorless, odorless, non-metal, single valency, and is a diatomic gas is highly flammable. With an atomic mass of 1.00794 amu, hydrogen is the lightest element in the world.

Hydrogen also is the most abundant element in the percentage of approximately 75% of the total mass of the universe elements. Most of the stars in a state formed by hydrogen plasma. Hydrogen compounds are relatively rare and seldom found naturally in the earth, and are usually generated from a variety of industrial compounds such as methane hydrocarbons. Hydrogen can also be produced from water through electrolysis, but the process is more expensive commercially than hydrogen production from natural gas.

Hydrogen isotopes are most often found in nature is protium, which the nucleus has only a single proton and no neutrons. Ionic compound hydrogen can be charged positively (cation) or negative (anions). Hydrogen can form compounds with most elements and can be found in water and organic compounds. Hydrogen is very important in acid-base reaction in which many reactions involve the exchange of protons between soluble molecules. Because hydrogen is the only neutral atom Schrödingernya equations can be solved analytically, study of the energetics and bonding of hydrogen atoms play a very important role in the development of quantum mechanics.



Thermochemical.
Solubility of hydrogen with various metals is a subject that is very important in the field of metallurgy as perapuhan hydrogen can occur on most metals in research and development of a safe way to save the hydrogen as fuel. Hydrogen is soluble in many compounds composed of nadir earth metals and transition metals and can be dissolved in crystalline metals and amorphous metals. Solubility of hydrogen in metals is caused by local distortions or impurities in the metal crystal kekisi.

There are more than 352 thermochemical process that can be used for the process of splitting or termolisis in this way we do not require electrical current but the only source of heat. Some thermochemical process is CeO2/Ce2O3, Fe3O4/FeO, SI, Ce-Cl, Fe, Cl and others. Reaski the terjdi in this process are:

2H2O -> 2H2 + O2

And all the materials used can be recycled back into new processes

Nature of Physics and Chemistry of Hydrogen

Physical properties

     * Melting point: -259.140 C
     * Boiling Point: -252.87 0C
     * Color: colorless
     * Odor: odorless
     * Density: 0.08988 g/cm3 at 293 K
     * Heat capacity: 14.304 J / GK

Chemical properties

     * Heat fusion: 0.117 kJ / mol H2
     * 1st ionization energy: 1312 kJmol
     * Electron affinity: 72.7711 kJ / mol
     * Heat atomization: 218 kJ / mol
     * Heat of vaporization: 0.904 kJ / mol H2
     * Number of skins: 1
     * The oxidation state of Minimum: -1
     * Electronegativity: 2.18 (scale Pauli)
     * Config electrons: 1s1
     * The maximum oxidation state: 1
     * Volume of polarization: 0.7 A3
     * Structure: HCP (hexagonal close-packed) (solid H2)
     * Atomic radii: 25 pm
     * Thermal conductivity: 0.1805 W / mK
     * The atomic weight: 1.0079
     * Potential ionization: 13.5984 eV
 
Source of Hydrogen in Natural 
Rarely found in the form of the element hydrogen (H2) in the wild (the earth). In ordinary conditions hydrogen gas contained in the H2 diatomic gas where it can get out of the earth's atmosphere due to its molecular weight is light. Hydrogen is the third element in the earth's most numerous on earth is the hydrogen content of 1400 ppm (0.14 wt%) or 2.9% mol. Hydrogen is present in its free state are found in gases released by volcanoes and in some places natural gas refineries. Caused by hydrogen is a reactive element hydrogen is commonly found in the form senyawaanya earth in the form of hydrocarbons such as methane and water. Several types of bacteria and algae producing hydrogen gas in the system metabolimesnya.

In our solar system is contained in an amount of hydrogen is very abundant and it ranged 75% by weight and 93% mol. In the universe of hydrogen was found as a constituent stars and planets are very large. Dijagat highway there in the form of atomic hydrogen and in the form of plasma in which the nature is different from ordinary molecular hydrogen. In the form of plasma electrons and protons are not hydrogen bonded together so this is producing electrical conductivity and level emisifitas (producing light) is high. Meanwhile, in the form of neutral atomic hydrogen in the universe there are at medium Interstellar matter that make up the stars that generally consist of gas and dust outer space.

The hydrogen content of the Earth's atmosphere is estimated at between 15000-20000 (in the number of molecules), and this value rises with increasing altitude atmosphere. And water is a cheap source of hydrogen other than hydrocarbons.

Tidak ada komentar:

Posting Komentar