Question

An ionic crystal lattice has r+/r- radius ratio of 0.320, its Co-ordination number is

Answer 1

the coordination number is 4.

Answer 2

Answer: The coordination number is 4.

Explanation:

0.155 to 0.225 for 3 coordination number

0.225 to 0.414 for 4 coordination number

0.414 to 0.732 for 6 coordination number

0.732 to 1 for 8 coordination number

Radius ratio = $\frac{\text{Radius of the cation}}{\text{Radius of the anion}}$

The radius ratio of the ionic crystal lattice = $\frac{r_+}{r_-}=0.320$

The radius ratio given for the crystal lattice is 0.320 which lies in between the range of 0.225 to 0.414 of coordination number 4.