A FCC crystal of O2− (oxide) ion has Mnn+ ions in all octahedral voids. Then value of n is
(1) 4
(2) 1
(3) 2
(4) 3
∴ Total no. of octahedral voids = 4
Number of Mn+ particles = 4
As all O.V. are occupied by Mn+.
∴ Formula of compound is M4O4
4n + (-2)4 = 0
n = 84
n = 2
Hence, option (3) is correct.