Question

We did not find results for: c=49.98%,h=5.19%,n=28.85%,o=16.48% the molar mass of caffeine is 194.19 g/mol. find the molecular formula of caffeine

Answer 1

First establish that your going to measure using 1 mole 
So now you have 194.19g caffeine 

Carbon is 49.48% of the mass 
so you have (49.48%)*(194.19)=96.0852 g carbon 
to see how many carbons you have you do (mass/Molar mass) 
(96.0852/12.0107) = 10 
So you have 10 carbons 

Do it for each one: 
Hydrogen: 
(5.19%)*(194.19) = 10.0785 g 
(mass/molar mass) (10.0785/1.00794) = 10 

Nitrogen: 
(28.85%)(194.19) = 56.0238 g 
(56.0238/14.00674) = 4 

Oxygen: 
(16.48%)(194.19) = 32.0025g 
(32.0025/15.9994) = 2 

Final formula: C8 H10 N4 O2