On complete combustion, a 44-gram sample of a compound gives 88 grams of CO₂ and 36 grams of H₂O. The molecular formula of the compound may be:
Correct answer: D. C₂H₄O
- A. C₄H₆
- B. C₂H₆O
- C. C₂H₄O₂
- D. C₂H₄O
Explanation
The products correspond to 2 moles of C (from 88g CO₂) and 4 moles of H (from 36g H₂O). The mass of C+H is 28g. The remaining mass of the sample (44g - 28g = 16g) must be oxygen, which is 1 mole of O. The formula is C₂H₄O.
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About Fundamental Concepts of Chemistry
Mole calculations connect mass, number of particles and Avogadro's number, while balanced equations provide the mole ratios used in stoichiometry. Questions cover limiting and excess reactants, theoretical yield and percentage yield, including identifying which reactant is consumed first and comparing the actual product with the maximum possible product.
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