In a solid, oxide ion are arranged in CCP. one sixth of tetrahedral voids are occupied by the cation A . while one third of the octahedral voids are occupied by cations B . what is the formula of the compound?
1. If n Oxide ions form the close packing----nO,
There will be 2n tetrhehral void, as 1/6 are occupied by A----2nX1/6 = n/3B
There will be n octahedral voids 1/3 are occupied by B---nX1/3 = n/3B
Ratio of A:B;O = n/3A : n/3B : nO
formulas are written in whole number multiply by 3.
A : B : 3O
the formula is ABO3