question_answer

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     AIEEE  Solved  Paper-2005

A) \[{{A}_{3}}B\]                                   

B) \[A{{B}_{3}}\]                   

C) \[{{A}_{2}}B\]                   

D)        \[AB\]

Correct Answer: B

Solution :

Unit cell consists of A ions at the corners. Thus number of ions of the type Unit cell consists of B ions at the centre of the six faces. Thus number of ions of the type (each corners is shared by 8 cubes and each face is shared by 2 faces) Ratio of number of ions Thus, formula is.