Tutton's salt

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Tutton's salts are a family of salts with the formula M2M'(SO4)2.(H2O)6(sulfates) or M2M'(SeO4)2.(H2O)6 (selenates). These materials are "double salts," which means that they contain two different cations, M+ and M'2+. Some examples of Tutton salts are, M = NH4+ and M' = V2+ and Cu2+.[1]
They are sometimes called Schonites after the naturally occurring mineral Schönite (K2MgSO4.6H2O). They are named for A.E H Tutton who identified and characterised a large range of these salts around 1900.[2]
Related to the Tutton's salts are the alums, which are also double salts but with the formula MM'(SO4)2.(H2O)12. The Tutton's salts were once termed "false alums"[3]. Such salts were of historical importance because they were obtainable in high purity and served as reliable reagents and spectroscopic standards.

[edit] References

  1. ^ Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements, 2nd Edition, Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4. 
  2. ^ A. E. Tutton (1900-1901). "A Comparative Crystallographical Study of the Double Selenates of the Series R2M(SeO4)2.6H2O.--Salts in Which M Is Zinc.". Proceedings of the Royal Society of London 67: 58-84. 
  3. ^ F.Sherwood Taylor (1942) Inorganic and Theoretical Chemistry 6th Edition, William Heinemann