Moderate

0.078 g of hydrocarbon occupies 22.4 ml of volume at 1 atm and 0˚C. The empirical formula of the hydrocarbon is CH. The molecular formula is:

Correct answer: C. C6H6

  • A. C2H2
  • B. C2H4
  • C. C6H6
  • D. C8H8

Explanation

PV = nRT n = PV/RT = 1 x 0.224 L / 0.08206 x 273 n = 0.001 mole Molar mass = 0.078/0.001 = 78 g Empirical formula = CH Mass according to Empirical formula = 12 + 1 = 13 Molecular formula = 78/13 = 6 That gives us C6H6.

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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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