24. Caffeine consists of carbon, hydrogen, oxygen, and nitrogen. When 0.1920 g of caffeine is burned in an excess of oxygen, 0.3482 g of carbon dioxide and 0.0891 g water are formed. Caffeine is 28.84% nitrogen by mass. Its molar mass is between 190 and 200 g/mol. What is the formula for caffeine?
(A) C₄H₅N₂O
(B) C₃H₂N₂O₂
(C) C₆H₄N₄O₄
(D) C₈H₁₀N₄O₂
(E) none of these

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