Question

An ionic compound axby occurs in fcc type crystal structure .The ion b at the centre of each face and a ions occupies corners of the cube. Calculate the value of x and y .Write the formula of the ionic compound.

Answer 1

Answer:

The formula of the ionic compound is $a_1b_3$

Explanation:

Number of 'a' atoms = $\frac{1}{8}\times 8=1$

One atom is shared by eight corners of 8 different cubic lattice.

Number of 'b' atoms = $\frac{1}{2}\times 6=3$

One atom is shared by two faces of the cubic lattice

The value of x = 1

The value of y = 3

The formula of the ionic compound is $a_1b_3$