MolSynapsequestion bank
MolSynapse / Question bank / Mole Concept / Average molar mass of mixtures, vapour density
JEE Advanced levelOne or more correct optionsDifficulty 3 of 3mc220

A hydrocarbon has a vapour density of and contains carbon by mass (C = 12, H = 1). Select the correct statement(s).

  1. A of it contains 0.08 mol of carbon atoms.
  2. BIts empirical formula is .
  3. CIts empirical formula mass is .
  4. DIts molecular formula is .

Answer: A, B, D

M = 2 x 53 = 106. In 100 g: C = 7.547 mol, H = 9.43 mol, ratio = 4 : 5, so the empirical formula is C4H5 (mass 53). n = 106/53 = 2 gives C8H10. 1.06 g = 0.0100 mol, containing 0.0100 x 8 = 0.08 mol C.
Practice Mole Concept More on Average molar mass of mixtures, vapour density
Previous question

More questions on Average molar mass of mixtures, vapour density