Question

A solid is made of two elements $X$ and $Z$. The atoms $Z$ are in $ccp$ arrangement while atoms $X$ occupy all the tetrahedral sites. What is the formula of the compound ?

• A. $XZ$
• B. $XZ_2$
• C. $X_2Z$
• D. Unpredictable

Answer 1

Answer: (C)

$X_2Z$

Answer 2

Let the number of atoms $Z$ in the CCP arrangement = $100$ Thus the number of tetrahedral sites = $200$ Since all the tetrahedral sites are occupied by atoms $X$, the number of atoms $X = 200$ Hence ratio of $X : Z = 2 : 1$ Thus the formula is $X_2Z$