Final answer:
The empirical formula for halothane is C2HBrClF3, which is determined by dividing the given mass percentages by the atomic masses of each element, then expressing the resulting mole ratios in the smallest whole numbers.
Step-by-step explanation:
To find the empirical formula for halothane based on its composition percentages, we divide each percentage by the respective element's atomic mass to get the mole ratio. Assuming we have 100 g of halothane (to make the math easier), we would calculate as follows:
- Carbon: 12.15% ÷ 12.01 g/mol = 1.011 mol
- Fluorine: 28.86% ÷ 19.00 g/mol = 1.518 mol
- Hydrogen: 0.506% ÷ 1.01 g/mol = 0.501 mol
- Bromine: 40.5% ÷ 79.90 g/mol = 0.507 mol
- Chlorine: 17.97% ÷ 35.45 g/mol = 0.507 mol
Next, we divide each mole quantity by the smallest mole quantity found, which is 0.501 mol of hydrogen, to find the simplest whole number ratio.
- C: 1.011 ÷ 0.501 ≈ 2
- F: 1.518 ÷ 0.501 ≈ 3
- H: 0.501 ÷ 0.501 = 1
- Br: 0.507 ÷ 0.501 ≈ 1
- Cl: 0.507 ÷ 0.501 ≈ 1
The empirical formula for halothane is thus C2HBrClF3.