Solid State Question 60
Question: A molecule $ A_2B $ (Mwt. = 166.4) occupies triclinic lattice with a $ 5\overset{o}{\mathop{A}},b=8\overset{o}{\mathop{A}}, $ and $ c=4\overset{o}{\mathop{A}}. $ If the density of $ AB_2 $ is $ 5.2gc{{m}^{-3}} $ , the number of molecules present in one unit cell is
Options:
A) 2
B) 3
C) 4
D) 5
Show Answer
Answer:
Correct Answer: B
Solution:
[b] Volume of unit cell $ =a\times b\times c $
$ =5\times {{10}^{-8}}\times 8\times {{10}^{-8}}\times 4\times {{10}^{-8}} $
$ =1.6\times {{10}^{-22}}cm^{3} $ Mass of unit cell $ =1.6\times {{10}^{-22}}\times 5.2 $
$ =8.32\times {{10}^{-22}}g $ Number of molecules in one unit cell $ =\frac{8.32\times {{10}^{-22}}}{166.4gmo{{l}^{-1}}}=3 $
BETA
