In a crystalline solid, anions `B` are arranged in ccp structure. Cations `A` are equally distributed between octahedral and tetrahedral voids if all the octahedral voids are occupied the formula of the ionic solids will be

Answer

`A_(2)B`

Explanation

Let the number of anions B = n
The number of octahedral voids = n
The number of tetrahedral voids = 2n
Since both the octahedral and tetrahedral voids are equally occupied, by cations A and also the octahedral voids are occupied (given), this means that n cations A present in octahedral voids and n cations A present in tetrahedral voids.
In other words, corresponding to n anions B, there are n + n = 2n cations.
The cations A and anions B are in the ratio = 2n : n = 2 : 1
Formula of solid = `A_(2)B`.