Question

Antifluorite structure is derived from fluorite structure by :

• A. heating fluorite crystal
• B. subjecting fluorite structure to high pressure
• C. interchanging the positions of positive and negative ions in the lattice
• D. by replacing smaller cation with a cation larger than the anion

Answer 1

The correct option is C interchanging the positions of positive and negative ions in the lattice

Antifluorite structure is derived from fluorite structure by interchanging the positions of positive and negative ions in the lattice.

$Ca{F}_2$ has fluorite type structure.

$C{a}^{2+}$ ions occupy ccp and $F^{-}$ ions occupy all the tetrahedral voids.

$N{a}_{2}O$ has antifluorite type structure.

$O^{2-}$ ions occupy ccp and $N{a}^{+}$ occupy all the tetrahedral voids.