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AP EAMCET · Chemistry · Solid State

In a crystal lattice, anions \(A\) forms hcp array, \(2 / 3\) of the tetrahedral voids are occupied by cations \(C\). What is the formula of crystal?

  1. A \(C_3 A_4\)
  2. B \(\mathrm{C}_4 \mathrm{~A}_3\)
  3. C \(C_2 A_3\)
  4. D \(C_3 A_2\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(\mathrm{C}_4 \mathrm{~A}_3\)

Step-by-step Solution

Detailed explanation

For hexagonal close packed ( \(h c p)\) crystal, there are 6 atoms per unit cell. That means anion \(A=\) number of octahedral voids \(=\) number of atoms per unit cell \(=6\). We also know that, tetrahedral voids \(=2 \times\) octahedral voids .…