Structure of a mixed oxide is cubic close-packed (c.c.p)the cubic unit cell of mixed oxide is composed of oxide ions. One fourth of the tetrahral voids are occupied by divalent metal A and the octahedral voids are occupied by a monovalent metal B. the formula of the oxide is :

Structure of a mixed oxide is cubic close-packed (c.c.p)the cubic unit

1.	Structure of a mixed oxide is cubic close-packed (c.c.p)the cubic unit cell of mixed oxide is composed of oxide ions. One fourth of the tetrahral voids are occupied by divalent metal A and the octahedral voids are occupied by a monovalent metal B. the formula of the oxide is :
Answer» `A_(2)B_(3)O_(4)` `AB_(2)O_(2)` `ABO_(2)` `A_(2)BO_(2)` Solution :Suppose number of ` O^(2-)`ions in close PACKING = n No. of octahedral VOIDS = n No. of tetradral voids = 2n Divalent METAL ions A present = `(2n)/4 = n/2 ` Monovalent metal ions B present =n Ratio `A :B : O^(2-) = n/2 : n :n = 1/2 :1:1 ` Hence, formula = ` AB_(2)O_(2)`