Question

A units cell of $BaCl_{2}$ (fluorite structure) is made up of

• A. Four$Ba^{2 +}$ions and four $Cl^{-}$ions
• B. Four $Ba^{2 +}$ions and Eight$Cl^{-}$ions
• C. Eight $Ba^{2 +}$ions and four $Cl^{-}$ions
• D. Four $Ba^{2 +}$ ions and six $Cl^{-}$ions.

Answer 1

Answer: (C)

Eight $Ba^{2 +}$ions and four $Cl^{-}$ions

Answer 2

In fluorite structure, cations form ccp structure and anions are present in all tetrahedral holes.

Hence, no. of $Ba^{2 +}$ions = 8 and no. of $Cl^{-}$ions = 4.