A carbon compound containing carbon and oxygen has an approximate molar mass of 290. On analysis, it is found to contain 50% by mass of each element. The molecular formula of the compound is:
Correct answer: A. C₁₂O₉
- A. C₁₂O₉
- B. C₄O₃
- C. C₃O₄
- D. C₉O₁₂
Explanation
From the 50% mass data, the empirical formula is found to be C₄O₃ (mass = 96 g/mol). The ratio of molar mass to empirical mass is n = 290/96 ≈ 3. Therefore, the molecular formula is (C₄O₃)₃ or C₁₂O₉.
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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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