Question

In a crystalline solid, the atoms A and B are arranged as follows :

a. Atoms A are arranged in ccp array. 

b. Atoms B occupy all the octahedral voids and half of the tetrahedral voids. What is the formula of the compound?

Answer 1

Let no. of atoms of A be N 

No. of octahedral voids = N  

No. of tetrahedral voids= 2N 

(i) There will be one atom of b in the octahedral void   

(ii) There will be one atom of B in the tetrahedral void (1/2*2N) 

Therefore, total 2 atoms of b for each atom of A   

Therefore formula of the compound =AB₂