Question

Predict the coordination number of ca2+ in cao crystal and also its crystal structure

Answer 1

Hello buddy,

● Answer -
CN of Ca2+ = 6
CaO => FCC structure

● Explaination -
- In CaO crystal, Ca2+ is a cation and O2- is an anion.
- Cationic (Ca2+) radius is 100 pm and anionic (O2-) radius is 145 pm.

Ratio of cationic/anionic radius is -
r+/r- = 100 / 145
r+/r- = 0.69

As 0.414 < 0.69 < 0.732, CaO will form FCC lattice.

Coordination number in FCC lattice is 6, therefore CN of Ca2+ must be 6.


Hope this cleared your queries.