In magnetite , `O^(2-)` have ccp arrangement with `Fe^(2+)` ions in `1//8^(th)` tetrahedral voids and `Fe^(3+)` occupy half of octahedral void .The formula of magnetite is

Options

A. `Fe_3O_4`
B. `Fe_2O_3`
C. `FeO`
D. `Fe_3O_8`

Answer

A

Explanation

No. of `O^(2-)` ions in ccp = 4
There will be 8 tetrahedral sites and 4 octahedral sites
No. of `Fe^(2+)` ions = `1/8 xx 8 = 1`
No. of `Fe^(3+)` ions = `1/8 xx 8 + 1/4 xx 4 = 2`
Formula of magnetite : `Fe^(2+) Fe_(2)^(3+) O_(4)^(2-) ~= Fe_(3)O_(4)`.