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Phosphates, Vanadates, Arsenates, Tungstates, and Molybdates. GLY 4200 Lab 9 - Fall, 2012. Phosphates, Vanadates, and Arsenates. Groups are tetrahedral, with strong bonding with in the group PO 4 3- , VO 4 3- , AsO 4 3- What is the charge on the cation?. Apatite.
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Phosphates, Vanadates, Arsenates, Tungstates, and Molybdates GLY 4200 Lab 9 - Fall, 2012
Phosphates, Vanadates, and Arsenates • Groups are tetrahedral, with strong bonding with in the group • PO43-, VO43-, AsO43- • What is the charge on the cation?
Apatite • Most important phosphate mineral • Major ore of phosphorous • Ca5(PO4)3(F,Cl, OH) • Occurs in three varieties • Fluor • Chlor • Hydroxy
Phosphates and Radiation • Uranium occurs in many phosphate group minerals, making them radioactive • The mining of phosphate ores often releases radioactivity into the environment • Houses built on or around phosphate gangue material may be plagued by high radon concentrations as a result
Tungstates and Molybdates • Cations are quite large • W and Mo have nearly identical radii – why? • Anionic groups are distorted square planar rather than tetrahedral
Extensive Partial Solid Solution • Involves both cations and anionic groups • Cation substitution – • Wolframite series – complete solid solution • FeWO4, Ferberite • MnWO4, Huebnerite • Wulfenite – PbMoO4 • Partial series to Powellite, CaMoO4
Anionic Substitution • Partial solid solution • CaWO4, Scheelite • CaMoO4, Powellite
Text Reference • See chapter 17 in the text for more information on phosphates, vanadates, arsenates, tungstates, and molybdates, pp. 405-406 and 425-433