Question:
The empirical formula for a compound with a cubic close packed arrangement of anions and with cations occupying all the octahedral sites in $\mathrm{A}_{\mathrm{x}} \mathrm{B}$. The value of $\mathrm{x}$ is
(Integer answer)
Solution:
Anions froms $\mathrm{CCP}$ or $\mathrm{FCC}\left(\mathrm{A}^{-}\right)=4 \mathrm{~A}^{-}$per unit cell Cations occupy all octahedral voids $\left(\mathrm{B}^{+}\right)=4 \mathrm{~B}^{+}$per unit cell
cell formula $\rightarrow \mathrm{A}_{4} \mathrm{~B}_{4}$
Empirical formula $\rightarrow \mathrm{AB}$
$\rightarrow(\mathrm{x}=1)$