Solid State Question 259
Question: PbS has NaCl type structure. The distance between $ P{{b}^{2+}} $ and $ {{S}^{2-}} $ ions is 297 pm. What is the volume of unit cell of PbS-
Options:
A) $ 209.6\times {{10}^{-24}}cm^{3} $
B) $ 207.8\times {{10}^{-23}}cm^{3} $
C) $ 22.3\times {{10}^{-23}}cm^{3} $
D) $ 209.8\times {{10}^{-23}}cm^{3} $
Show Answer
Answer:
Correct Answer: A
Solution:
[a] $ ({r _{pb^{2}}}+{r _{{{S}^{2-}}}})=\frac{a}{2} $ Edge length of unit cell $ =2\times 297pm $ $ =594\times {{10}^{-10}}cm $ Volume of unit cell $ ={{(594\times {{10}^{-10}})}^{3}}cm=209.6\times {{10}^{-24}}cm^{3} $
BETA
