Question

If the radius of cation is 96 pm and that of anion is 618 pm. Determine the coordination number and structure of the crystal lattice. 

Answer 1

Given: Radius of cation (r+ ) = 96 pm

Radius of anion (r− ) = 618 pm 

To find:

i. Coordination number = ? 

ii. Structure of the crystal lattice = ?

Formula:

Radius ratio= Radius of the cation/Radius of the anion

Calculation: 

From formula,  

Since the radius ratio lies in between 0.155 – 0.225 

The coordination number of crystal is 3 And the structure of crystal lattice is Trigonal planar.