Solid State Question 266
Question: The spinel structure ( $ AB_2O_4 $ ) consists of an fee array of $ {{O}^{2-}} $ ions in which the:
Options:
A) A cation occupies one-eighth of the tetrahedral holes and B cation occupies half of octahedral holes
B) A cation occupies one-fourth of the tetrahedral holes and the B cations the octahedral holes
C) A cation occupies one-eighth of the octahedral hole and the B cation the tetrahedral holes
D) A cation occupies one-fourth of the octahedral holes and the B cations the tetrahedral holes
Show Answer
Answer:
Correct Answer: A
Solution:
[a] fcc array $ \Rightarrow $ no. of $ {{O}^{2-}} $ ions=4 no. of TVs=8 and OVs=4 $ A\to \frac{1}{8}\times 8=1,B\to 4\times \frac{1}{2}=2 $ and $ {{O}^{2-}}=4 $ so formula of spinel $ =AB_2O_4 $
BETA
