Some Basic Concepts Of Chemistry Question 191
Question: Caffeine has a molecular weight of 194. If it contains 28.9% by mass of nitrogen, number of atoms of nitrogen in one molecule of caffeine is
Options:
A) 4
B) 6
C) 2
D) 3
Show Answer
Answer:
Correct Answer: A
Solution:
100gm caffeine has 28.9gm nitrogen 194gm caffeine has = $ \frac{28.9}{100}\times 194=56.06gm $
$ \therefore $ No. of atoms in caffeine $ =\frac{56.06}{14}\approx 4 $ .
