Question

Column 1: Type of structure, Column 2: Co-ordination number of cation, Column 3: Co-ordination number of anion.

$\begin{array}{cccccc}& \text{Column 1}& & \text{Column 2}& & \text{Column 3}\\ \text{(I)}& \text{FCC}& \text{(i)}& 12& \text{(P)}& 4\\ \text{(II)}& \text{Anti-Flourite}& \text{(ii)}& 6& \text{(Q)}& 12\\ \text{(III)}& \text{BCC}& \text{(iii)}& 8& \text{(R)}& 8\\ \text{(IV)}& \text{Flourite}& \text{(iv)}& 4& \text{(S)}& 6\end{array}$

The only correct combination for $Ca{F}_2$ is:

• A. (II) (iii) (P)
• B. (II) (iv) (R)
• C. (IV) (iv) (R)
• D. (IV) (iii) (P)

Answer 1

The correct option is D

(IV) (iii) (P)

$Ca{F}_2$ has fluorite structure with 8 : 4 coordination number (cation : anion). Ca occupies all the tetrahedral voids.