In spinel structure, `O^(2-)` ions are cubic-closed packed, wherease 1/8th of the tetrahedral holes are occupied by `A^(2+)` cations and 1/2 of the octahedral holes are occupied by cations `B^(3+)` . The general formula of this compound is

Options

A. `A_2BO_4`
B. `AB_2O_4`
C. `A_2B_4O`
D. `A_4B_2O`

Answer

B

Explanation

No. of `O^(2-)` ions in ccp arrangement = 4
No. of octahedral holes = 4
No. of `B^(3+)` ions = `4 xx 1/2 = 2`
No. of tetrahedral holes = `4 xx 2 = 8`
No. of `A^(2+)` ions = `8 xx 1/8 = 1`
Formula `A B_2O_4`.