Chemical Thermodynamics of Tin - Volume 12 - OECD Nuclear ...

256
A Discussion of selected references
Tin(II) oxide hydrates:
1) SnO·2.23H 2 O SnO·2H 2 O 1
2) SnO·0.73H 2 O 3SnO·2H 2 O
Basic tin(II) chlorides:
1) SnCl 0.39 O 0.79·1.14H 2 O SnCl 2·4SnO·6H 2 O
2) SnCl 0.79 O 0.61·1.23H 2 O 2SnCl 2·3SnO·6H 2 O
3) SnCl 1.00 O 0.50·1.92H 2 O SnCl 2·SnO·4H 2 O
Basic tin(II) sulfates:
1) Sn 3 O 1.99 (SO 4 ) 1.01·1.04H 2 O Sn 3 (OH) 2 OSO 4
2) Sn 3 O 1.98 (SO 4 ) 1.02 Sn 3 O 2 SO 4
The methods used in analysing the substances were not reported. The
stoichiometric formula of the only crystallised tin(II) hydroxide oxide turned out to be
3SnO·H 2 O [1968HOW/MOS], thus Ditte’s analyses reflect the difficulty to remove
adhering water from the precipitated product completely.
It turned out that hydrolysis of tin(II) in aqueous, chloride containing solutions
gives abhurite, Sn 21 Cl 16 (OH) 14 O 6 as the sole well crystallised solid phase at low pH.
Thus the solids obtained by Ditte’s synthetic procedures are probably mixtures of
abhurite and tin(II) hydroxide oxide or tin(II) chloride oxide [1981SCH/NES],
[1992EDW/GIL].
The basic tin(II) sulfate, Sn 3 (OH) 2 OSO 4 , is indeed a corrosion product found
on the surfaces of tin and its alloys.
[1897YOU]
In preparation of SnI 2 partly formed SnI 4 was extracted by CS 2 and SnI 2 stored in CS 2 .
SnI 2 (s) was stirred in a 100 cm 3 test tube with solvent. After heating to near boiling the
tube was put into a beaker with water. Temperature was read from an inserted
thermometer inside the tube and samples were drawn from time to time weighed and
analysed (titration of tin(II) with iodine), see Figure A-1.
The second series of measurements seems to be more reliable. Equilibration
time is unknown and may be in the range of minutes. The author states that the results
are not of high accuracy.
1 The mathematical symbol means corresponds to, see [2007COH/CVI].
CHEMICAL THERMODYNAMICS OF TIN, ISBN 978-92-64-99206-1, © OECD 2012