Question

In a compound, atoms of element Y form ccp lattice and those of element X occupy \( \frac{2}{3} \)rd of tetrahedral voids. The formula of the compound will be:

• A. \( X_4Y_3 \)
• B. \( X_3Y_3 \)
• C. \( X_4Y_7 \)
• D. \( X_3Y_4 \)

Hint:

In a ccp structure, the number of tetrahedral voids equals the number of atoms in the unit cell. The number of voids occupied by element X can be used to determine the stoichiometry of the compound.

Answer 1

The Correct Option is A

Step 1: In a ccp lattice, each unit cell contains 4 atoms of element Y.
Step 2: The number of tetrahedral voids in a ccp structure is also 4, and \( \frac{2}{3} \) of these voids are occupied by element X.
Step 3: Therefore, the number of atoms of element X is \( 4 \times \frac{2}{3} = 3 \), and the number of atoms of element Y is 4. Thus, the formula is \( X_4Y_3 \).

Final Answer: \[ \boxed{X_4Y_3} \]