The spinel structure $\left(A{B}_2{O}_4\right)$ consists of an fcc array of $O^{2-}$ ions in which the

Q. In normal spinel structure ($A{B}_2{O}_4$), there is a closed packed array of $O^{2-}$ ions. The trivalent cations are present in:

Q. In spinel structure, oxides ions form fcc lattice, whereas $\frac{1}{8}$th of tetrahedral holes are occupied by cations $A^{2+}$ and $\frac{1}{2}$ of octahedral holes are occupied by cations $B^{3+}$ ions. The general formula of the compound having spinel structure is

Q. A compound with formula $A{B}_2{O}_4$ adopts a crystal structure in which $O^{2-}$ ions forms ccp arrangement. $A^{2+}$ ions occupy octahedral voids while $B^{3+}$ ions are distributed equally between tetrahedral and octahedral voids. The fraction of octahedral and tetrahedral voids occupied respectively are:

Q. Spinel is an important class of oxides consisting of two types of metal ions with the oxide ions arranged in CCP pattern. The normal spinel has one-eighth of the tetrahedral holes occupied by one type of metal ion and half of the octahedral hole occupied by another type of metal ion. Such a spinel is formed by $Z{n}^{2+}$, $A{l}^{3+}$ and $O^{2-}$ with $Z{n}^{2+}$ in the tetrahedral holes. The formula of the spinel is:

Q. In a normal spinal structure, there is a closed packed array of $O^{2-}$ ions. The trivalent cations are present in: