Question

CsCl has ______ Coordination.

• A. 6:6
• B. 8: 8
• C. 4:8
• D. 8:4

Answer 1

The correct option is B

8: 8

Do you remember the structure of CsCl compound?

If not, Let’s revise it together.

It has body-centered cubic (bcc) arrangement.

Each $C{s}^{\oplus }$ ion is surrounded by eight $C{l}^{⊝}$ ions and each $C{l}^{⊝}$ ion is surrounded by eight $C{s}^{\oplus }$ ions, i.e., this structure has 8: 8 coordination.

A unit cell of CsCl consists of only one unit of CsCl, i.e., one $C{s}^{\oplus }$ ion and one $C{l}^{⊝}$ ion (because each ion present at the corner is shared by eight unit cells) [The ratio $\frac{r_{Cs\oplus }}{r_{Cl⊝}}$ = 0.93 which is greater than expected for exact fitting (0.732)].

So, you got it right.

It has 8:8 coordination.