1. 1 Phosphates, Vanadates, Arsenates, Tungstates, and Molybdates GLY 4200 Lab 9 - Fall, 2015

2. 2 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?

3. 3 Apatite Most important phosphate mineral Major ore of phosphorous Ca 5 (PO 4 ) 3 (F,Cl, OH) Occurs in three varieties  Fluor  Chlor  Hydroxy

4. 4 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

5. 5 Tungstates and Molybdates Cations are quite large W and Mo have nearly identical radii – why? Anionic groups are distorted square planar rather than tetrahedral

6. 6 Extensive Partial Solid Solution Involves both cations and anionic groups Cation substitution –  Wolframite series – complete solid solution FeWO 4, Ferberite MnWO 4, Huebnerite  Wulfenite – PbMoO 4 Partial series to Powellite, CaMoO 4

7. 7 Anionic Substitution Partial solid solution  CaWO 4, Scheelite  CaMoO 4, Powellite

8. Text Reference See chapter 17 in the text for more information on phosphates, vanadates, arsenates, tungstates, and molybdates, pp. 405-406 and 425-433 8