Nitrogen

characteristics
carbon - nitrogen - oxygen N P [He] 2s 2 2p 3 14 7 N < div id= " box2 " style= " boron that: solvently 1px black; position: absolute; top: 10px; left: 224px; width: 7px; height: 9px; OVERFLOW: hidden; “/> Periodic system
generally
name, symbol, ordinal number	nitrogen, N, 7
series	of nonmetals
Group, period, block	15, 2, p
appearance	colorless
proportion at the Earth's shell	0.03%
atomically
atomic mass	14.0067 u
atomic radius (computed)	65 (56) pm
Kovalenter radius	75 pm
van the Waals radius	155 pm
Elektronenkonfiguration	[He] 2s 2 2p 3
electrons per energy level	2, 5
1. Ionization energy	1402.3 kJ/mol
2. Ionization energy	2856 kJ/mol
3. Ionization energy	4578.1 kJ/mol
4. Ionization energy	7475.0 kJ/mol
5. Ionization energy	9444.9 kJ/mol
6. Ionization energy	53266.6 kJ/mol
7. Ionization energy	64360 kJ/mol
physically
state of aggregation	gaseously
Modifications	1
crystal structure	hexagonally
density (Mohshärte)	1.2506 kg/m 3 (with 273 K) (-)
magnetism	-
melting point	63.14 K (- 210.01 ° C)
boiling point	77.35 K (- 195.80 °C)
molecular volume	22,4 · 10 -3 m 3 /mol
heat of vaporization	2,7928 kJ/mol
heat of fusion	0.3604 kJ/mol
steam pressure	-
speed of sound	334 m/s with 298,15 K
specific thermal capacity	1040 j (kg · K)
Electrical conductivity	-
heat conductivity	0.02598 w (m · K)
Chemically
oxidation conditions	of -3, 2, 3, 4, 5
hydrides and oxides (Basicity)	(strongly sourly)
normal potential	-
Elektronegativität	of 3.04 (Pauling scale)
isotopes
isotope NH t 1/2 ZM CPU M eV ZP 13 N {syn.} 9.965 m ε 2.220 13 C 14 N 99.634% N is stable with 7 Neutrons 15 N 0.366% N is stable with 8 neutrons 16 N {syn.} 7.13 s β - 10.419 16 O
as far as possible and common, are used SI-UNITs. If not differently notes, the indicated data apply with standard conditions.

The name nitrogen (Nitrogenium) designates the chemical element from the periodic system of the elements with the symbol N and the ordinal number 7. One speaks also of atomic nitrogen. Elementarily nitrogen steps however only in form of a kovalenten Homodimers, a chemical compound from two nitrogen atoms, on (→ molecular nitrogen, also these ticking off (see. Disauerstoff), sum formula N ₂).

Molecular nitrogen is a main part of air. It is in the environment an important fertilizer, thatby nitrogen adjustment on natural way in the humus one enriches. In atomic form it is as component of the proteins an important main feeding element of all organisms. Nitrogen is a central element in the Stickstoffkreislauf of the ecological systems and became, there it in minerals relativelyarises rarely, on the earth's surface and in the water almost exclusively biotisch enriched.

The element symbol N leads itself from that latin designation nitrogenium (of altgriech. νιτρον „caustic solution salt “and altgriech. γενος „origin “) off. The German designation nitrogen reminds of the fact that molecular nitrogen Flames deletes („suffocates “) or some organism (e.g. humans) in pure nitrogen suffocates.

Table of contents 1 history 2 natural occurrence and cycle of the nitrogen 2,1 nitrogen in air 2,2 nitrogen in the soil 3 production/representation 4 characteristics of 5 isotopes 6 Connections 7 use 8 proof of 9 Web on the left of

history

nitrate and ammonium salts were already used by Alchemisten. Carl William cross-eyed one knows 1771 nitrogen as a component of air after. For the first time in the year 1774 ammonia was represented by Joseph Priestley.By the introduction of the franc Caro procedure (lime ticking off production after Adolph franc and NIC edema Caro) atmospheric nitrogen became for the first time at the beginning 20. Jh. usable made. Likewise at the beginning 20. Century became industrially available further important procedures. Among these procedures rank among other thingsthe production of nitric acid (Birkeland Eyde procedure, after Kristian Birkeland and SAM Eyde), the catalytic ammonia burn after William Ostwald as well as the ammonia synthesis after Fritz Haber and Carl Bosch. 1906 succeeded it the Netherlands physicist Heike Kamerlingh Onnes to liquid nitrogen for the first timeto manufacture with -195,80 °C.

in the last century one already recognized

natural occurrence and cycle of the nitrogen that a large part contains nitrogen of the vegetable substance. Nitrogen is an important element of the plant. It is the substantial elementthe proteins and Proteide (protein materials). In addition, nitrogen is component of the enzymes, which steer the vegetable, animal and human metabolism. Nitrogen is indispensable for each life.

nitrogen in air

the mantle of air of the earth exists too78% from N. Only a small number of micro organisms can transform, into its body substance build or also at plants deliver the molecular N of air. Plants cannot use the gaseous N of air directly. The transfer of the gaseousNitrogen of atmospheric air into a N-form, which is usable by the plants, is done via

• Knöllchenbakterien: These very small organisms penetrate into the Leguminosenwurzeln. They nourish themselves of the Assimilaten of the plant. In the exchange for it they supply with to thatPlant host nitrogen, which they take up directly from air. This partnership is called symbiosis. It occurs with higher plants with Leguminosen .
• Free-living micro organisms: The nichtsymbiotische nitrogen connection rests on the ability of some free-living micro organisms (e.g. Azotobacter) and Algae to use atmospheric nitrogen for the setting up from body-own protein to. In the case of field-structural use the order of magnitude of the connection of atmospheric nitrogen is accepted by free-living micro organisms with 5-15kg/ha and year.
• Electrical discharge with thunderstorms: In precipitation-rich areas annually 20-25kg can N/ha and year by rainfalls the soil to be supplied.
• Ammonia synthesis: The chemists Haber and Bosch have 20 at the beginning. Century a procedure develops, with which of atmospheric nitrogen and hydrogen ammonia can be made. By the Haber/Bosch procedurepossible use of the inexhaustible N-supply of the atmosphere become contributed in the past decades substantially to the Leistungsteigerung of agricultural production. The securing of food supply of the population of world could be substantially improved thereby. The plant composes vegetable protein of that taken up nitrogen, thatHumans and animal as food and for the setting up the own body protein serve. In the human and animal organism the protein is to a large extent again diminished and separated with the excrement and urine.

nitrogen in the soil

in thatTop soil (A-horizon) usually more soil organisms are present as 95% of the entire n than organically bound nitrogen in living Wurzelmasse, died plant mass, humus materials and. The remainder of less than 5% is inorganic nitrogen in the form of ammonium - N or nitrate - N andin very small quantity in the form of nitrite - N. The total nitrogen content of the soils depends strongly on their carbon content. It is affected by climate and vegetation , soil type, area shape and measures of the farmer, like cultivation]].

production/representation

Primarily nitrogen is won today by the fractionated distillation of liquefied air. This is however mostly still contaminated by oxygen and noble gases. For removing the remaining oxygen there is a biological method using rice - Keimlingen.

Industriallytakes place the production of nitrogen in the context of the Haber-Bosch-process to ammonia - the synthesis.

Another possibility is binding the atmospheric oxygen under heating up to coal and following washing of the developed carbon dioxide. The atmospheric oxygen can also by thatLead up air over glowing copper or by an alkaline Pyrogallol - and/or. Sodium dithionite - solution to be removed.

In the laboratory pure nitrogen knows aqueous ammonium nitrite by heating up on - a solution or a solution of the mixture ammonium chloride/Natriumnitrit about 70 °C are represented:

<math> \ mathrm {NH_4NO_2 + \ delta} T \ mathrm {\ rightarrow 2H_2O + N_2}< /math>

Alternatively a Thermolyse of sodium azide is possible, which is used for the representation by spectroscopically pure nitrogen.

<math> \ mathrm {2NaN_3 + \ delta} T \ mathrm {\ rightarrow 2Na + 3N_2}< /math>

characteristics

molecular nitrogen is a color, a smelland tasteless gas, which at low temperatures (- 196°C) to a colorless liquid condenses. Nitrogen is in water a little solubly (23.2 ml nitrogen in 1 l water with 0 °C) and not inflammable.

Nitrogen goes to preferably kovalente connections in its connections. In the 2s ² p ³ Elektronenkonfiguration leads the formation of three Kovalenzen to Oktett - the completion. Connections, in which this connection type occurs, are for example:

• Ammonia
• of amines
• hydrazine
• Hydroxylamin

these connections is all a trigonale pyramidale structure and a freePair of electrons too own. Over this free pair of electrons these connections can act as Nukleophile and as Basen.

The molecular these ticking off occurring in nature N ₂ is by in the nitrogen molecule existing the stable triple bond and the associated high connection dissociation energy of942 kJ/mol very poorly reactively. According to the required activation energy, which can be reduced if necessary by suitable catalysts , is high.

In a publication in August 2004 researchers of the institute for Max-Planck for chemistry publication in Mainz that her under pressures from over110 G Pa at a temperature of over 2000 K a new crystalline form, so-called polymere nitrogen with single bonds produced [1].

14

N and 15 N there ^are isotopes beside the two natural isotopes artificialIsotopes with mass numbers from 12 to 19. Their radioactive half-life amounts to between 9.97 minutes and 11 milliseconds.

connections

connections, in which nitrogen occurs:

• Nitrogen monoxide
• nitrogen dioxide
• Stickstofftetroxid
• dinitrogen oxide
• amino acids
• of Peptide
• of proteins
• sperm cellses
• iodine ticking off
• of coloring materials
• of nitrate, nitrites, Nitrides

use

technical nitrogen becomes the synthesis of ammonia (Haber-Bosch-process) and lime ticking off as well as inert gas when welding, when lamp filling uses and with chemical reactions. Beyond that nitrogen compounds find various applications within the range of the organicAnd serve chemistry as fertilizers.

Nitrogen is used for the filling of aircraft tires of large airplanes. The pure nitrogen prevents that aircraft tires touch down by large heat development with during the landing in fire turn out from the inside can.

The disputed filling of Motor-car tire with nitrogen is brought up for discussion in the article “tire gas “.

Nitrogen finds in beverage tapping plants use, if due to of structural circumstances (long routing, large difference in height), a high tapping pressure becomes necessary. Nitrogen is used here together with carbon dioxide as Dowson gas. Therenitrogen not in the beverage separates, can even with higher pressures without too much foaming power and/or. Aufcarbonisierung to be tapped.

Due to the small boiling point liquid nitrogen is used as cooling medium in the cryogenics. The nitrogen extracts thereby the necessary from the cooling property Heat of vaporization. In relation to the use of liquid oxygen with similar boiling point the inert characteristics of the nitrogen are favourable. Liquid nitrogen is used for the cooling of high temperature superconductors as well as for the storage of biological and medical samples. In the foundation engineering it is used for soil freezing up.

proof

nitrogen, which is present in organically bound form, can be seized qualitatively by means of Lassaigne sample and quantitatively by means of the Kjeldahl Stickstoffbestimmung or elementary analysis. For inorganically bound nitrogen the cross sample for ammonium ions or the ring sample becomes as proof reaction for nitrate ions accomplished. For the execution of the ring sample the sample solution (sulfur-sourly, heavy metal-free) with fresh iron ii-sulfate solution is shifted and under-laminated with concentrated sulfuric acid. At the boundary surface between both liquids the nitrate ions are reduced to nitrogen monoxide (NO). This radical forms in aqueous solutionwith further iron ions a brown complex, which becomes visible as “ring” at the phase boundary in the test tube:

1. Step: 3 Fe ²⁺ + NO ₃ ^- + H ⁺ <math> \ rightarrow </math> 3 Fe ³⁺ + NO + 2 H ₂O (redox reaction) and

2. Step: Fe ²⁺ + NO + 5 H ₂ O <math> \ rightarrow </math> [Fe (H ₂ O) ₅ NO] ²⁺ (complex education reaction)

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