Solid State Question 227
Question: In the calcium fluoride structure the co-ordination number of the cation and anions are respectively
[J & K 2005]
Options:
A) 6, 6
B) 8, 4
C) 4, 4
D) 4, 8
Show Answer
Answer:
Correct Answer: B
Solution:
The $ C{{a}^{2+}} $ ions are arranged in (ccp) arrangement, i.e. $ C{{a}^{2+}} $ ions are present at all corners and tat the center of each face of the cube.
the fluoride ions occupy all the tetrahedral sites.
This is 8 : 4 arrangement i.e., each $ C{{a}^{2+}} $ ion is surrounded by $ 8{{F}^{-}} $ ions and each $ {{F}^{-}} $ ion by four $ C{{a}^{2+}} $ ions.
BETA
