Oxygen containing compounds of nitrogen
Dinitrogen monoxide, N2O. It is a gas colorless and any smell known as “exhilarant gas(laughing?!)”, as it has a narcotic action b.p. = -890С, it is well dissolved in water: 0.6 volume in 1 volume of H2O.
The chemical structure|building| of molecule of N2O can be presented by the chart:
In accordance with sp-hybridization the molecule of N2O has a linear structure|building|:
N-=N+=O NN+—O- N-=N+—O-
Preparation. In laboratory:
1. Thermal decomposition of ammonium nitrate (or hydroxylamine nitrite|):
2. Weak heating of sulfaminic| acid with HNO3:
HNO3 + NH2SO2OH = N2O + H2SO4 + H2O
By chemical properties N2O is a nonsaltforming oxide.
At the weak heating it is decomposed:
2N2O = 2N2 + O2
that is why|that is why| N2O is a strong oxidant:
N2O + H2 = N2 + H2O
3N2O + 2NH3 = 4N2 + 3H2O
N2O + H2SO3 = N2 + H2SO4
Cu + N2O = N2 + CuO
N2O does not interact with water, thou hyponitrous, | acid H2N2O2, in which|what| nitrogen has an oxidation state (+1) is known. Its structure has two equivalent atoms of nitrogen.
Free H2N2O2 is isolated|receive|:
It|it| is well dissolved in water, but as an acid it is very weak (К1 = 10-8, К2 = 10-12). H2N2O2 is very unstable, at even slight heating it explodes:
H2N2O2 = N2O + H2O
Nitrogen mooxide, NO. It is a gas without color and smell (b.p. = -152 oС), not soluble in water. A candle does not burn|burning| in NO, red phosphorus however burns|burning| [explanation - like burning of magnesium in N2].
In nature it forms at thunderstorm discharges|discharge,rank|:
O2 + hv Oo + Oo;
Oo + N2 NO + No;
No + O2 NO + Oo and others
NO is unique|single,sole,only,common| compound as it is the only oxide of nitrogen which|what| can be prepared|received| by direct|immediate| interaction of elements.
Preparation. In a laboratory:
3Cu + 8HNO3(dilut) = 2NO + 3Cu(NO3)2 + 4H2O
In industry:
4NH3 + 5O2 = 4NO + 6H2O
Properties|virtue|. For nitrogen mathematically even oxidation states (+2, +4) are comparatively little characteristic|character,typical|. NO belongs|behave| to|by| the number of such compounds|halving,compound,junction,joint,coupling|. The molecule of NO is paramagnetic, that is deduced out of МО method|. The molecule of NO contains|maintain| the odd number of electrons. Compared with N2 molecule (according to МО| method N2 [KK 2s2*2s22p2y2p2z2p2x]) an additional electron is contained|maintained| on antibonding orbitals|, that is why|that is why| the order of bond in the molecule of NO (according the method of МО| NO[KK 2s2*2s22p2y2pz2p2x*2py])is equal 2,5:
.
For this reason the molecule of NO is not decomposed back to the elements, although it|it| endothermic and has a positive|staid| G of formation|formation| from elements.
Without regard to|in spite of,regardless of| the enormous amount|quantity| of researches, devoted to the structure|building| of NO, it is still an «enigmatic» molecule: it|it| is|appear| odd numbered, as it contains|maintain| 11 valency electrons, but it is little inclined|liable,predisposed,located| to|by| dimerization|. Only at low temperatures it|it| is dimerized| onto (NO)2 - a compound of dark blue color, but not completly (even at -163оС only at 95%), and only the solid NO is dimerized| by 100%. Other properties|virtue| of NO are also unusual: through|from,because of| a unpaired| electron it is paramagnetic, but this compound is for some reason uncolorless as compared to other even molecules it is sufficiently|enough| stable (thermally) and relatively|in relation to| low reactive|clever|.
NO is a paramagnetic molecule, that is why|that is why| tries|attempt,endeavour| to give|return| or to add an electron:
1) NO -e- NO+ -9,3 В nitrosyl|
This ion it forms on such conditions:
N2O3 + 3H2SO4 = 2NO+ + 3HSO4- + H3O+
Nitrosonium| hydogen sulfate, NO+HSO4- (nitrosylsulfuric| acid) is an intermediate| in the tower method of preparation of H2SO4. Other salts of nitrosonium are known: NO+ClO4- NO+BF4-. Salts of nitrosonium |are| easily hydrolysed:
NO+ + H2O = H+ + HNO2
2) NO + e- NO-
Such salts are formed at interaction of Na and NO in liquid|rare,thin| ammonia:
Na + NO Na + NO-
NO demonstrates oxidizing and reductive properties|virtue|.
Oxidizing properties|virtue| (nature of products depends on reductant property|power| of a partner and conditions of reaction):
2NO + 2H2 = N2 + H2O
3H2O + 2NO + 3H2SO3 = 2NH2OH + 3H2SO4
5CrCl2 + NO + 4H2O = NH3 + 5Cr(OH)Cl2
NO + 2SO2 = 2SO3 + N2
4NO + 2KOH = N2O + 2KNO2 + H2O last two proceed
6NO + 4KOH = N2 + 4KNO2 + 2H2O parallel
Reducing properties|virtue|:
2NO + HClO3 + H2O = 2HNO3 + HCl
2NO + O2 = 2NO2 (in the air instantly) Но = -113,4 kJ/mol
2NO + O3 = N2O5 + O2
6NO + 3KMnO4 + H2SO4 = 5HNO3 + 3MnSO4 + K2SO4 + KNO3
NO interacts with Cl2 with the formation of NOCl – nitrosyl chloride|:
2NO + Cl2 = 2NOCl.
It is a yellow gas, b.p. = -6 oС. NOCl is a chloranhydride of nitrous acid:
NOCl + H2O = HNO2 + HСl
NOCl + 2KOH = KNO2 + KCl + H2O
with water NO does not form compounds|halving,compound,junction,joint,coupling|, although corresponding hyponitric| acid H2N2O3 and its salts (hyponitrites|) are known, |what| nitrogen there also has an oxidation state +2. Compound H2N2O3 is a weak acid (К1 = 9.10-8, К2 = 1.10-11), it can be prepared in the following way|received|:
NH2OH + HNO2 = H2N2O3 + H2O