Question

In a binary compound, atoms of element A form a hcp structure and those of element M occupy `2/3` of the tetrahedral voids of 3 the hcp structure. The formula of the binary compound is ______.

Options

• M₂A₃

• M₄A₃

• M₄A

• MA₄

Answer 1

In a binary compound, atoms of element A form a hcp structure and those of element M occupy `2/3` of the tetrahedral voids of 3 the hcp structure. The formula of the binary compound is `bbunderline(M_4A_3)`.

Explanation:

In hcp structure, number of tetrahedral voids = 2 × number of atoms of A. 

Let number of A atoms = 3 (for calculation ease).

Tetrahedral voids = 2 × 3 = 6.

M atoms occupy `2/3` of these voids:

= `2/3 xx 6`

Ratio of the compound = M : A = 4 : 3

The formula of the binary compound is M₄A₃.