Question

The atoms of element 'Y' form hexagonal close packing and the atoms of element X occupies `3/4` th portion of the number of tetrahedral voids. The formula of the compound formed by X and Y is ____________.

Options

• X₂Y₂

• X₂Y

• X₃Y₂

• X₄Y₃

Answer 1

The atoms of element 'Y' form hexagonal close packing and the atoms of element X occupies `3/4` th portion of the number of tetrahedral voids. The formula of the compound formed by X and Y is X₃Y₂.

Explanation:

Let the number of atoms of element Y in hcp unit cell be n.

∴ Number of tetrahedral voids = 2n

As `(2/3)^"rd"` of the tetrahedral voids are occupied by atoms of element X,

Number of atoms of element X = `2"n" xx 3/4 = (3"n")/2`

∴ Ratio of atoms of element X : atoms of element Y = `(3"n")/2 : "n"` = 3 : 2

The formula of the compound is X₃Y₂.