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Chambers, Holliday. Modern inorganic chemistry (1975)(T)(459s)_Ch_.djvu |
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containing this ion are known, for example nitrosyl tetrafluoroborate,
(NO)+(BF4)~, and nitrosyl hydrogensulphate, (N0)+(HS04)~...
With alkalis, a mixture of
nitrite and nitrate is formed:
2OH" + 2NO2 -» NO3- + NO2 + H2O
Dinitrogen tetroxide, N2O4, as a liquid, has some power as a
solvent, and appears to dissociate slightly to give nitrosyl nitrate,
thus:
N2O4 ^ NO+ + NO3-
If metallic zinc is dissolved in this liquid, the following reaction
occurs:
Zn + 2N2O4 -» Zn(NO3J + 2NOt
i.e...
It is prepared by burning phosphorus
in a plentiful supply of air or oxygen:
P4 + 5O2 - P4O10
It is a white, deliquescent solid, very powdery, which exhibits
polymorphism; on heating, several different crystalline forms appear
over definite ranges of temperature -ultimately, the P4O10 unit in
the crystal disappears and a polymerised glass is obtained, which
melts to a clear liquid...
Here the nitrogen
dioxide dissolves to give nitric acid and nitrogen oxide; air is also
passed up the tower to oxidise the latter to give more nitrogen
dioxide, which is absorbed in turn, so that ultimately almost
complete conversion of the nitrogen oxides to nitric acid is complete;
the acid is collected, at a strength of 50-65 %, at the base of the tower...
For example, copper in cold nitric acid A:1) reacts
thus:
3Cu + 8HNO3 -> 3Cu(NO3J + 2NOT + 4H2O
In concentrated nitric acid (when warmed) the reaction is:
Cu + 4HNO3 -> Cu(NO3J + 2NO2 + 2H2O
Metals which do liberate hydrogen from dilute acids, for example
zinc, magnesium, can react with nitric acid to give dinitrogen oxide,
for example:
4Zn + IOHNO3 -> 4Zn(NO3J + N2O + 5H2O
and if the hydrogen ion content of the nitric acid is further increased,
by adding dilute sulphuric acid, hydroxylamine or ammonia is
formed...
Two kinds are
known, trioxoarsenates(III), for example Na3AsO3, and dioxo-
arsenates(III), for example Cu(AsO2J...
Phosphorus pentachloride sublimes and then dissociates on
heating, dissociation being complete at 600 K...
It dissolves in water, but on dilution partial hydrolysis
occurs and antimony chloride oxide SbOCl is precipitated:
[Sb3+] + CP + H2O ^2H+ + O=Sb—Cl
(Here again the simple formulation [Sb3+] is used to represent all
the cationic species present.) The hydrolysis is reversible and the
precipitate dissolves in hydrochloric acid and the trichloride is
reformed...
In America, the sulphur deposits (mostly in Louisiana and Texas)
are dome-shaped layers about 30 cm thick, between limestone
above and anhydrite below...
Ozone, O3, is found in trace quantities in the upper atmosphere
where it is believed to be formed by the photochemical dissociation
of oxygen molecules by the intense ultra-violet light from the sun;
GROUP VI 263
absorption of this light in the process prevents it from reaching the
earth where it would destroy all living matter very rapidly...
The oxidation of the
iodide ion to iodine in solution is used to determine ozone quanti-
quantitatively...
Further, the sulphite ion can add
on a sulphur atom to give the thiosulphate ion, S2O2~ which is
also found in the reaction mixture...
SOLVENT PROPERTIES
The high permittivity (dielectric constant) makes water a highly
effective solvent for ionic crystals, since the electrostatic attractive
forces between oppositely charged ions are reduced when the crystal
is placed in water...
In acid solution, dichromates(VI) (and also chromates(VI)
which are converted to dichromates) are reduced to chromium(III)
salts:
Cr2O?- + 8H+ + 3H2S - 2Cr3+ + 7H2O + 3S|
(Hence the orange colour of a dichromate is converted to the green
colour of the hydrated chromium(III) ion, Cr3+, and sulphur is
precipitated when hydrogen sulphide is passed through an acid
solution.)
5...
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