Nickel sulphate heptahydrate

Beevers, C. A. and Schwarz, C. M. (1935). The crystal structure of nickel sulphate heptahydrate NiS04- 7H2O. Zeit. Kristallogr. 91, 157-69. 

Fig. 12.16. Plan of the unit cell of the orthorhombic structure of nickel sulphate heptahydrate, Ni(H20)6S04.H20, projected on a plane perpendicular to the z axis. The heights of atoms are indicated in units of c/ioo and hydrogen bonds are represented by broken lines. The heights marked have been expressed in such a way as to emphasize the co-ordination round the nickel and sulphur atoms, but in considering the distribution of the hydrogen bonds it must be remembered that an atom at a height, say, — 7 lies outside the cell but is repeated within the cell at a height 93. Some or all of the neighbours of any given oxygen atom or water molecule may therefore be not those marked but others displaced above or below them by a distance c.

Fig. 12.17. The bond structure in nickel sulphate heptahydrate, Ni(H20)6S04.H20. This diagram must be interpreted in the sense that it represents correctly the coordination of each atom or molecule considered separately, but not the detailed co-ordination in the structure as a whole. Thus the water molecule Ac is shown to be bonded to two oxygen atoms but it must not be assumed that they belong to a single SO4 group in fact they do not, as can be seen from fig. 12.16.

Results of study of the decomposition of nickel sulphate heptahydrate through nickel sulphate hexahydrate and nickel sulphate tetrahydrate at 0.015 bar (II torr) are presented. X-ray diffraction patterns are presented for some of the different solids. Detailed measurement results were not tabulated, but the graphical presentation and the reported thermodynamic quantities for the dehydration reactions are in reasonable agreement with results reported in the later study of Kohler and Zaske [64KOH/ZAS]. 

Reactions in which the number of growth nuclei formed in a given time have been observed experimentally are rather few in number, and for many decompositions the law of nucleus formation has been inferred from the kinetics rather than determined by direct observation. Notable exceptions are barium azide( ) oz t nickel sulphate heptahydrate( ) oc and copper sulphate pentahydrate and chrome alum( ) oc /. 

Nickelous Sulphate or Nickel Sulphate, NiS04, has been obtained in various stages of hydration. Its solution is prepared by dissolving the hydroxide or carbonate in dilute sulphuric acid. When crystallised at 15-20° C., the heptahydrate, NiS04.7H20, is obtained as green rhombic prisms, isomorphous with the corresponding ferrous and zinc sulphates. Its density 7 is 1-877, and specific heat 0-341. 

EINECS 232-104-9 HSDB 1114 NCI-C60344 Nickel sulfate Nickel sulfate (NiS04) Nickel sulfate(1 1) Nickel sulphate Nickel(2+) sulfate Nickel(ll) sulfate Nickelous sulfate NSC 51152 Sulfuric acid, nickel(2+) salt (1 1) Sulphuric acid, nickel(ll) salt. Also occurs as the hexahydrate [10101-97-0 232-104-9] and the heptahydrate [10101-98-1 205-788-1]. Used in the electroplating trade, Hexahydrate loses 5H2O at 100 and becomes anhydrous at 280. Soluble in H2O (0.7 g/ml) LDso (gpg sc) 62 mg/kg. 

NAN/DES] Nandi, P. N., Deshpande, D. A., Kher, V. G., Thermogravimetric analysis of hexa- and heptahydrate crystals and packed powder of nickel sulphate, Thermochim. Acta, 32, (1979), 143-149. Cited on page 193. 

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