Suppose an ionic solid with a cubic unit cell contains a (cations) and z (anions). the a ions are in the body center position and at each corner, and the z ions are on each face. based on this structure the empirical formula of the compound would be az

The empirical formula of the compound would be

Explanation:

The A ions are in the body center position and at each corner .

There are 8 faces of the cube and 1 corner is also shared by another 7 cubic unit.

Then number of A ion in a cubic unit =

The Z ions are on each face of the cubic unit :

There are 6 faces of the cube and 1 face is shared by another cubic unit.

Then number of Z ions in a cubic unit =

The structural formula of the cubic lattice is  =

Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.

The empirical formula of the compound would be