W(CI) = 35, W(O) =64% W(H)=1%

Interpretation: The given percentages are mass percentages of H, Cl, and O in a compound.

• H = 1%, Cl (CI) = 35%, O = 64%
• Assume 100 g sample:
  • H: 1 g / 1.01 ≈ 0.99 mol
  • Cl: 35 g / 35.45 ≈ 0.99 mol
  • O: 64 g / 16.00 ≈ 4.00 mol
• Divide by the smallest number (≈0.99): H ≈ 1, Cl ≈ 1, O ≈ 4

Empirical formula: HClO4

The molecular formula is HClO4 (perchloric acid) since its molar mass is about 100.46 g/mol, matching the given mass percentages.