Question

why Cscl is more stable than the structure of NaCl?What is the name of the structure poseesed by CsCl?

Answer 1

The stability of CsCl and NaCl, depends on two factors:

1. The cations and anions should touch each other.
2. The compoud should attain maximum possible coordination number.

Now, the radius ratio of NaCl (Coordination number 6) is in the range of 0.414-0.732, while that of CsCl (Coordination number 8) is 0.732-1.00. It shows that, in CsCl, the size of cation and anion is close to each other, they are touching each other, while this is not so in NaCl. Also, the coordination number of CsCl is more than that of NaCl, these facts make the structure of CsCl more stable than NaCl.

The type of structure possessed by CsCl is Body-centered cubic lattice.