Question

A compound $M_{p}X_{p}$ has cubic close packing (ccp) arrangement of $X$ . Its unit cell structure is shown in figure. The empirical formula of the compound is :

• A. $MX$
• B. $MX_{2}$
• C. $M_{2}X$
• D. $M_{5}X_{14}$

Answer 1

Answer: (B)

$M_{p}X_{q}$ has ccp structure, therefore
$x=8\times \frac{1}{8}+6\times \frac{1}{2}=4$
$M=4\times \frac{1}{4}+1=2$
So unit cell formula of the compound is $M_{2}X_{4}$ and the empirical formula of the compound is $MX_{2}$ .