Question

Atoms C and D form fcc crystalline structure. Atom C is present at the corners of the cube and D is at the faces of the cube. What is the formula of the compound?

• A. $C{D}_2$
• B. $C_{3}D$
• C. ${CD}_3$
• D. None of these

Answer 1

Answer: (C)

${CD}_3$

Here, $C$ and $D$ forms FCC crystalline structure.

Since, $C$ is present at corners of the cube.

So, effective number of atoms of $C=\frac{1}{8}\times 8=1$

Now, $D$ is present ad faces of the cube (i.e at face centers)

So, effective number of atoms of $D=\frac{1}{2}\times 6=3$

So, formula of compound is $C{D}_3$.

Hence, option C is correct.