Question

An ionic compound has a unit cell consisting of ‘A’ ions at the corners of a cube and ‘B’ ions on the centres of the faces of the cube. The empirical formula for this compound would be

• A. $AB$
• B. $A_{2}B$
• C. $A{B}_3$
• D. $A_{3}B$

Answer 1

The correct option is C $A{B}_3$

Number of ‘A’ ions $=8\times \frac{1}{8}=1$
No. of ‘B’ ions = $=6\times \frac{1}{2}=3$
Formula = $A{B}_3$