Q113 / 200 · MHT CET - Medical 2026 (25 April Shift 2) · Chemistry
A solid is formed of two different elements, A and B. In this atoms of A are arranged in the CCP array, and atoms of B occupy all octahedral voids and half of tetrahedral voids. Find the formula of the solid.
- A$\text{AB}$
- B$\text{A}_2\text{B}$
- Correct answerC$\text{AB}_2$
- D$\text{AB}_3$
Solution
In a CCP lattice, the number of atoms per unit cell is $4$.
Number of atoms of A $= 4$
The number of octahedral voids is equal to the number of atoms in the lattice, which is $4$.
The number of tetrahedral voids is twice the number of atoms in the lattice, which is $8$.
Atoms of B occupy all octahedral voids and half of the tetrahedral voids.
Number of atoms of B $= 4 + \dfrac{1}{2} \times 8 = 4 + 4 = 8$
The ratio of atoms of A to atoms of B is $4 : 8 = 1 : 2$.
The formula of the solid is $\text{AB}_2$.
Answer: $\text{AB}_2$
Number of atoms of A $= 4$
The number of octahedral voids is equal to the number of atoms in the lattice, which is $4$.
The number of tetrahedral voids is twice the number of atoms in the lattice, which is $8$.
Atoms of B occupy all octahedral voids and half of the tetrahedral voids.
Number of atoms of B $= 4 + \dfrac{1}{2} \times 8 = 4 + 4 = 8$
The ratio of atoms of A to atoms of B is $4 : 8 = 1 : 2$.
The formula of the solid is $\text{AB}_2$.
Answer: $\text{AB}_2$
Hence, the correct answer is option: 'C'.