Some Basic Concepts Of Chemistry Question 158
Question: The sulphate of a metal M contains 9.87% of M. This sulphate is isomorphous with $ ZnSO _4.7H _2O $ . The atomic weight of M is [IIT 1991]
Options:
A) 40.3
B) 36.3
C) 24.3
D) 11.3
Show Answer
Answer:
Correct Answer: C
Solution:
As the given sulphate is isomorphous with $ ZnSO _4.7H _2O $ its formula would be $ MSO _4.7H _2O $ .m is the atomic weight of M, molecular weight of $ MSO _4.7H _2O $ $ =m+32+64+126 $ $ =m+222 $
Hence % of M $ =\frac{m}{m+222}\times 100 $ $ =9.87 $ (given) or $ 100m=9.87m+222\times 9.87 $ or $ 90.13m=222\times 9.87 $
or $ m=\frac{222\times 9.87}{90.13}=24.3 $ .
