Inorganic help! 8. The mineral pyrargyrite, Ag3Sbs3, utilizes the hexagonal latt
ID: 958857 • Letter: I
Question
Inorganic help!
8. The mineral pyrargyrite, Ag3Sbs3, utilizes the hexagonal lattice system. The sulfides are space-filling and the Ag ions occupy one sort of hole (either octahedral or tetrahedral) while the Sb+3 ions occupy the other sort of hole. (a) cation do you think occupies each hole and why? Why did you pick the one you did? (in 10 words or fewer) (b) What fraction of octahedral holes would be occupied with your model? (c) What fraction of tetrahedral holes would be occupied with your model?Explanation / Answer
There are 6 atoms in hcp structure. There are 6 octahedral holes and 12 tetrahedral holes in the unitcell.
As per molecular formula, there are sulfide ions equals to silver ions and 1/3 rd of the sites occupied by the antimony.Hence we conclude that 1/3rd of tetrahedral holes can be occupied by Sb and remaining occupied by Ag. Hence 4-Sb and 12-Ag atoms should be there in the given molecular formula.