If the molecular formulas of ethane, hydrogen chloride, and glucose are C2 H6, HCI, and C6 H12 O6 respectively, what will be their respective empirical formulas?

If the molecular formulas of ethane, hydrogen chloride, and glucose are C2 H6, HCI, and C6 H12 O6 respectively, what will be their respective empirical formulas? Correct Answer CH₃, HCI and CH₂O

The correct answer is CH3, HCI, and CH2O.

Key Points

• If the molecular formulas of ethane, hydrogen chloride, and glucose are C2 H₆, HCI, and C₆ H12 O6 respectively, then empirical formulas are CH₃, HCI and CH₂O respectively
• Hence, the correct option is 1.

Additional Information

• Empirical versus Molecular Formulas
  • The formulas we have calculated in the preceding section express the simplest atomic ratio between the elements in the compound.
    • Such formulas are called empirical formulas.
  • An empirical formula does not necessarily represent the actual numbers of atoms present in a molecule of a compound; it represents only the ratio between those numbers.
  • The actual numbers of atoms of each element that occur in the smallest freely existing unit or molecule of the compound are expressed by the molecular formula of the compound.
  • The molecular formula of a compound may be the empirical formula, or it may be a multiple of the empirical formula.
  • For example, the molecular formula of butane, C₄H₈, shows that each freely existing molecule of butene contains four atoms of carbon and eight atoms of hydrogen.
  • Its empirical formula is CH_2. One molecule of ethylene (molecular formula C₂H₄) contains two atoms of carbon and four atoms of hydrogen.
  • Its empirical formula is CH₂.
    • Both have the same empirical formula, yet they are different compounds with different molecular formulas.
  • Butene is C₄H₈, or four times the empirical formula; ethylene is C2H4 or twice the empirical formula.