Difference between revisions of "Nitrogen"
| Line 19: | Line 19: | ||
|alt names= | |alt names= | ||
|allotropes= | |allotropes= | ||
| − | |appearance= | + | |appearance=Colorless gas, liquid or solid |
<!-- Periodic table --> | <!-- Periodic table --> | ||
|above=- | |above=- | ||
| Line 26: | Line 26: | ||
|right=[[Oxygen]] | |right=[[Oxygen]] | ||
|number=7 | |number=7 | ||
| − | |atomic mass= | + | |atomic mass=14.007 |
|atomic mass 2= | |atomic mass 2= | ||
|atomic mass ref= | |atomic mass ref= | ||
| Line 36: | Line 36: | ||
|group=15 | |group=15 | ||
|group ref= | |group ref= | ||
| − | |group comment= | + | |group comment= (pnictogens) |
|period=2 | |period=2 | ||
|period ref= | |period ref= | ||
| Line 43: | Line 43: | ||
|block ref= | |block ref= | ||
|block comment= | |block comment= | ||
| − | |electron configuration= | + | |electron configuration=[He] 2s<sup>2</sup> 2p<sup>3</sup> |
|electron configuration ref= | |electron configuration ref= | ||
|electron configuration comment= | |electron configuration comment= | ||
| − | |electrons per shell= | + | |electrons per shell=2, 5 |
|electrons per shell ref= | |electrons per shell ref= | ||
|electrons per shell comment= | |electrons per shell comment= | ||
| Line 55: | Line 55: | ||
|phase ref= | |phase ref= | ||
|phase comment= | |phase comment= | ||
| − | |melting point K= | + | |melting point K=63.15 |
| − | |melting point C= | + | |melting point C=−210.0 |
| − | |melting point F= | + | |melting point F=−346.0 |
|melting point ref= | |melting point ref= | ||
|melting point comment= | |melting point comment= | ||
| − | |boiling point K= | + | |boiling point K=77.355 |
| − | |boiling point C= | + | |boiling point C=−195.795 |
| − | |boiling point F= | + | |boiling point F=−320.431 |
|boiling point ref= | |boiling point ref= | ||
|boiling point comment= | |boiling point comment= | ||
| Line 70: | Line 70: | ||
|sublimation point ref= | |sublimation point ref= | ||
|sublimation point comment= | |sublimation point comment= | ||
| − | |density gplstp= | + | |density gplstp=1.251 |
|density gplstp ref= | |density gplstp ref= | ||
|density gplstp comment= | |density gplstp comment= | ||
| Line 85: | Line 85: | ||
|density gpcm3mp ref= | |density gpcm3mp ref= | ||
|density gpcm3mp comment= | |density gpcm3mp comment= | ||
| − | |density gpcm3bp= | + | |density gpcm3bp=0.808 |
|density gpcm3bp ref= | |density gpcm3bp ref= | ||
|density gpcm3bp comment= | |density gpcm3bp comment= | ||
| Line 92: | Line 92: | ||
|molar volume ref= | |molar volume ref= | ||
|molar volume comment= | |molar volume comment= | ||
| − | |triple point K= | + | |triple point K=63.151 |
| − | |triple point kPa= | + | |triple point kPa=12.52 |
|triple point ref= | |triple point ref= | ||
|triple point comment= | |triple point comment= | ||
| Line 100: | Line 100: | ||
|triple point 2 ref= | |triple point 2 ref= | ||
|triple point 2 comment= | |triple point 2 comment= | ||
| − | |critical point K= | + | |critical point K=126.192 |
| − | |critical point MPa= | + | |critical point MPa=3.3958 |
|critical point ref= | |critical point ref= | ||
|critical point comment= | |critical point comment= | ||
| − | |heat fusion= | + | |heat fusion=0.72 |
|heat fusion ref= | |heat fusion ref= | ||
|heat fusion comment= | |heat fusion comment= | ||
| Line 110: | Line 110: | ||
|heat fusion 2 ref= | |heat fusion 2 ref= | ||
|heat fusion 2 comment= | |heat fusion 2 comment= | ||
| − | |heat vaporization= | + | |heat vaporization=5.56 |
|heat vaporization ref= | |heat vaporization ref= | ||
|heat vaporization comment= | |heat vaporization comment= | ||
| − | |heat capacity= | + | |heat capacity=29.124 |
|heat capacity ref= | |heat capacity ref= | ||
|heat capacity comment= | |heat capacity comment= | ||
| Line 119: | Line 119: | ||
|heat capacity 2 ref= | |heat capacity 2 ref= | ||
|heat capacity 2 comment= | |heat capacity 2 comment= | ||
| − | |vapor pressure 1= | + | |vapor pressure 1=37 |
| − | |vapor pressure 10= | + | |vapor pressure 10=41 |
| − | |vapor pressure 100= | + | |vapor pressure 100=46 |
| − | |vapor pressure 1 k= | + | |vapor pressure 1 k=53 |
| − | |vapor pressure 10 k= | + | |vapor pressure 10 k=62 |
| − | |vapor pressure 100 k= | + | |vapor pressure 100 k=77 |
|vapor pressure ref= | |vapor pressure ref= | ||
|vapor pressure comment= | |vapor pressure comment= | ||
| Line 137: | Line 137: | ||
<!-- Atomic properties --> | <!-- Atomic properties --> | ||
|atomic properties comment= | |atomic properties comment= | ||
| − | |oxidation states= | + | |oxidation states='''5''', 4, '''3''', 2, 1, −1, −2, '''−3''' |
|oxidation states ref= | |oxidation states ref= | ||
| − | |oxidation states comment= | + | |oxidation states comment=(a strongly acidic oxide) |
| − | |electronegativity= | + | |electronegativity=3.04 |
|electronegativity ref= | |electronegativity ref= | ||
|electronegativity comment= | |electronegativity comment= | ||
| − | |ionization energy 1= | + | |ionization energy 1=1402.3 |
|ionization energy 1 ref= | |ionization energy 1 ref= | ||
|ionization energy 1 comment= | |ionization energy 1 comment= | ||
| − | |ionization energy 2= | + | |ionization energy 2=2856.0 |
|ionization energy 2 ref= | |ionization energy 2 ref= | ||
|ionization energy 2 comment= | |ionization energy 2 comment= | ||
| − | |ionization energy 3= | + | |ionization energy 3=4578.1 |
|ionization energy 3 ref= | |ionization energy 3 ref= | ||
|ionization energy 3 comment= | |ionization energy 3 comment= | ||
| Line 161: | Line 161: | ||
|atomic radius calculated ref= | |atomic radius calculated ref= | ||
|atomic radius calculated comment= | |atomic radius calculated comment= | ||
| − | |covalent radius= | + | |covalent radius=71±1 |
|covalent radius ref= | |covalent radius ref= | ||
|covalent radius comment= | |covalent radius comment= | ||
| − | |Van der Waals radius= | + | |Van der Waals radius=155 |
|Van der Waals radius ref= | |Van der Waals radius ref= | ||
|Van der Waals radius comment= | |Van der Waals radius comment= | ||
| Line 171: | Line 171: | ||
|crystal structure prefix= | |crystal structure prefix= | ||
|crystal structure ref= | |crystal structure ref= | ||
| − | |crystal structure comment= | + | |crystal structure comment=Hexagonal |
|crystal structure 2= | |crystal structure 2= | ||
|crystal structure 2 prefix= | |crystal structure 2 prefix= | ||
|crystal structure 2 ref= | |crystal structure 2 ref= | ||
|crystal structure 2 comment= | |crystal structure 2 comment= | ||
| − | |speed of sound= | + | |speed of sound=353 |
|speed of sound ref= | |speed of sound ref= | ||
| − | |speed of sound comment= | + | |speed of sound comment=(gas, at 27 °C) |
|speed of sound rod at 20= | |speed of sound rod at 20= | ||
|speed of sound rod at 20 ref= | |speed of sound rod at 20 ref= | ||
| Line 191: | Line 191: | ||
|thermal expansion at 25 ref= | |thermal expansion at 25 ref= | ||
|thermal expansion at 25 comment= | |thermal expansion at 25 comment= | ||
| − | |thermal conductivity= | + | |thermal conductivity=25.83×10<sup>−3</sup> |
|thermal conductivity ref= | |thermal conductivity ref= | ||
|thermal conductivity comment= | |thermal conductivity comment= | ||
| Line 216: | Line 216: | ||
|Curie point ref= | |Curie point ref= | ||
|Curie point comment= | |Curie point comment= | ||
| − | |magnetic ordering= | + | |magnetic ordering=Diamagnetic |
|magnetic ordering ref= | |magnetic ordering ref= | ||
|magnetic ordering comment= | |magnetic ordering comment= | ||
| Line 246: | Line 246: | ||
|Brinell hardness ref= | |Brinell hardness ref= | ||
|Brinell hardness comment= | |Brinell hardness comment= | ||
| − | |CAS number= | + | |CAS number=17778-88-0<br>7727-37-9 (N<sub>2</sub>) |
|CAS number ref= | |CAS number ref= | ||
|CAS number comment= | |CAS number comment= | ||
| Line 254: | Line 254: | ||
|prediction date ref= | |prediction date ref= | ||
|prediction date= | |prediction date= | ||
| − | |discovered by= | + | |discovered by=Daniel Rutherford |
|discovery date ref= | |discovery date ref= | ||
| − | |discovery date= | + | |discovery date=1772 |
|first isolation by= | |first isolation by= | ||
|first isolation date ref= | |first isolation date ref= | ||
|first isolation date= | |first isolation date= | ||
|discovery and first isolation by= | |discovery and first isolation by= | ||
| − | |named by= | + | |named by= Jean-Antoine Chaptal |
|named date ref= | |named date ref= | ||
| − | |named date= | + | |named date=1790 |
|history comment label= | |history comment label= | ||
|history comment= | |history comment= | ||
Revision as of 18:59, 2 October 2017
 Nitrogen discharge tube. | |||||
| General properties | |||||
|---|---|---|---|---|---|
| Name, symbol | Nitrogen, N | ||||
| Alternative name | Azote | ||||
| Appearance | Colorless gas, liquid or solid | ||||
| Nitrogen in the periodic table | |||||
| |||||
| Atomic number | 7 | ||||
| Standard atomic weight (Ar) | 14.007 | ||||
| Group, block | (pnictogens); p-block | ||||
| Period | period 2 | ||||
| Electron configuration | [He] 2s2 2p3 | ||||
per shell | 2, 5 | ||||
| Physical properties | |||||
| Colorless | |||||
| Phase | Gas | ||||
| Melting point | 63.15 K (−210.0 °C, −346.0 °F) | ||||
| Boiling point | 77.355 K (−195.795 °C, −320.431 °F) | ||||
| Density at (0 °C and 101.325 kPa) | 1.251 g/L | ||||
| when liquid, at | 0.808 g/cm3 | ||||
| Triple point | 63.151 K, 12.52 kPa | ||||
| Critical point | 126.192 K, 3.3958 MPa | ||||
| Heat of fusion | 0.72 kJ/mol | ||||
| Heat of | 5.56 kJ/mol | ||||
| Molar heat capacity | 29.124 J/(mol·K) | ||||
| pressure | |||||
| Atomic properties | |||||
| Oxidation states | 5, 4, 3, 2, 1, −1, −2, −3 (a strongly acidic oxide) | ||||
| Electronegativity | Pauling scale: 3.04 | ||||
| energies |
1st: 1402.3 kJ/mol 2nd: 2856.0 kJ/mol 3rd: 4578.1 kJ/mol | ||||
| Covalent radius | 71±1 pm | ||||
| Van der Waals radius | 155 pm | ||||
| Miscellanea | |||||
| Crystal structure | Hexagonal | ||||
| Speed of sound | 353 m/s (gas, at 27 °C) | ||||
| Thermal conductivity | 25.83×10−3 W/(m·K) | ||||
| Magnetic ordering | Diamagnetic | ||||
| CAS Registry Number |
17778-88-0 7727-37-9 (N2) | ||||
| History | |||||
| Discovery | Daniel Rutherford (1772) | ||||
| Named by | Jean-Antoine Chaptal (1790) | ||||
Nitrogen is a chemical element with symbol N and atomic number 7. Nitrogen is a common element in the universe, estimated at about seventh in total abundance in our galaxy and the Solar System. On Earth, the element is primarily found as the gas molecule; it forms about 78% of Earth's atmosphere. The element nitrogen was discovered as a separable component of air, by Scottish physician Daniel Rutherford, in 1772.
Contents
Properties
Chemical
Nitrogen is a nonmetal, with an electronegativity of 3.04. It has five electrons in its outer shell and is, therefore, trivalent in most compounds. The triple bond in molecular nitrogen (N2) is one of the strongest. The resulting difficulty of converting nitrogen into other compounds, and the ease (and associated high energy release) of converting nitrogen compounds into elemental N2, have dominated the role of nitrogen in both nature and human economic activities.
While nitrogen is relative inert, certain metals such as magnesium or lithium will burn in a nitrogen atmosphere.
Physical
At room temperature, nitrogen is a colorless and odorless gas. At atmospheric pressure, molecular nitrogen condenses (liquefies) at 77 K (−195.79 °C) and freezes at 63 K (−210.01 °C) into the beta hexagonal close-packed crystal allotropic form. Below 35.4 K (−237.6 °C) nitrogen assumes the cubic crystal allotropic form (called the alpha phase). Liquid nitrogen, a fluid resembling water in appearance, but with 80.8% of the density (the density of liquid nitrogen at its boiling point is 0.808 g/mL), is a common cryogen.
Availability
Nitrogen cylinders can be bought at hardware stores and welding supply stores. Liquid nitrogen can be bought from chemical suppliers, and while it's not expensive, the container used for storage, Dewar, is.
Preparation
Nitrogen can be isolated from air via reduction of oxygen with copper turning or other reducing agents (except metals that will burn in a nitrogen atmosphere, such as lithium, magnesium or titanium). The purified gas will contain ~1% argon. Smaller, but purer amounts of nitrogen can also be obtained by decomposing sodium azide. Nitrous oxide can also be used.
Liquid nitrogen can be made at home, by employing an air compressor and a cooling installation. A good tutorial can be found here.
Projects
- Cooling baths (liquid nitrogen)
- Haber process (small scale)
- Make lithium nitride
- Inert atmosphere
Handling
Safety
Gaseous nitrogen is inert, but in an enclosed space at high concentrations can displace oxygen, and therefore presents an asphyxiation hazard.
Direct skin contact with liquid nitrogen will cause severe frostbite (cryogenic "burns"), either instantly or a second or more after direct exposure, depending on the form of liquid nitrogen.
Storage
Compressed nitrogen tanks should be stored away from any heat sources. Liquid nitrogen dewars should be kept away from any source of heat and light and MUST have a pressure release valve to prevent a pressure build-up. The valve must be checked from time to time for any problems.
Disposal
Nitrogen can be safely released in atmosphere. Avoid doing this in a closed chamber.
