Question

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

• A. AB
• B. A2B
• C. AB3
• D. A3B

Answer 1

Answer: (C)

AB3

Answer 2

Number of A ions per unit cell = $\frac{1}{8}$× 8 = 1

Number of B ions per unit cell = $\frac{1}{2}$× 6 = 3

Empirical formula = AB3.