Structure of a mixed oxide is cubic closed - packed (ccp) .The cubic unit cell of mixed oxide is composed of oxide ions .One fourth of the tetrahedral voids are occupied by divalent metal A and the octahedral voids are occupied by a monovelent metal B .The formula of the oxide is

Options

A. `A_2B_3O_4`
B. `AB_2O_2`
C. `ABO_2`
D. `A_2BO_2`

Answer

B

Explanation

Suppose number of `O^(2-)` ions in close packing =n
`therefore` No. of octahedral voids=n
No. of tetrahedral voids=2n
Divalent metal ions A present =`"2n"/4=n/2`
Monovalent Metal ions B present =n
`therefore` Ratio `A:B:O^(2-)=n/2:n:n=1/2:1:1`
Hence, formula =`AB_2O_2`