Question

A crystal formula ab3 has a ions at cube corners, and b at edge centres of cube, find cordination numbers of a and b

Answer 1

The options for this question are missing:

(A) 6 and 6

(B) 2 and 6

(C) 6 and 2

(D) 8 and  8

The correct answer for this question is (C) 6 and 2

Co - ordination of cation/ Co - ordination no of anion

= charge of  cation/ charge of anion = 3/1  = 3

(coordination number of A = 6)

Now co-ordination no of A is shown so B is 2