In a solid ,oxide `(O^(2-))` ions are arranged in ccp, cations `(A^(3+))` occupy one -sixth of tetrahedral void and cations `(B^(3+))` occupy one -third of the octahedral voids . What is the formula of the compound?

Explanation

Number of oxide ions forming ccp=4
(Occupy 8 corners and 6 faces centres )
Number of Tetrahedral voids =8
Number of octahedral voids =4
Number of cations A occupying Tetrahedral voids =`8/6`
Number of cations B occupying Octahedral voids =`4/3`
`A:B:O^(-2)`
`8/6:4/3:4`
8:8:24
`therefore` 1:1:3
And formula of compound is `ABO_3`