To calculate the percentage composition of oxygen in the given organic substance, follow these steps:
1. Determine the moles of carbon in the CO₂ produced:
- The molar mass of CO₂ is calculated as follows:
[tex]\[
\text{Molar mass of CO}_2 = \text{Molar mass of C} + 2 \times \text{Molar mass of O} = 12.01 \, \text{g/mol} + 2 \times 16.00 \, \text{g/mol} = 44.01 \, \text{g/mol}
\][/tex]
- Given the mass of CO₂ is 0.4950 g, the moles of CO₂ can be calculated using:
[tex]\[
\text{Moles of CO}_2 = \frac{\text{Mass of CO}_2}{\text{Molar mass of CO}_2} = \frac{0.4950 \, \text{g}}{44.01 \, \text{g/mol}} = 0.01125 \, \text{moles}
\][/tex]
- Since each mole of CO₂ contains one mole of carbon, the moles of carbon are equal to the moles of CO₂:
[tex]\[
\text{Moles of C} = 0.01125 \, \text{moles}
\][/tex]
- Calculate the mass of carbon using its molar mass:
[tex]\[
\text{Mass of C} = \text{Moles of C} \times \text{Molar mass of C} = 0.01125 \, \text{moles} \times 12.01 \, \text{g/mol} = 0.135 \, \text{g}
\][/tex]
2. Determine the moles of hydrogen in the H₂O produced:
- The molar mass of H₂O is calculated as follows:
[tex]\[
\text{Molar mass of H}_2\text{O} = 2 \times \text{Molar mass of H} + \text{Molar mass of O} = 2 \times 1.008 \, \text{g/mol} + 16.00 \, \text{g/mol} = 18.016 \, \text{g/mol}
\][/tex]
- Given the mass of H₂O is 0.2025 g, the moles of H₂O can be calculated using:
[tex]\[
\text{Moles of H}_2\text{O} = \frac{\text{Mass of H}_2\text{O}}{\text{Molar mass of H}_2\text{O}} = \frac{0.2025 \, \text{g}}{18.016 \, \text{g/mol}} = 0.01125 \, \text{moles}
\][/tex]
- Since each mole of H₂O contains two moles of hydrogen, the moles of hydrogen are:
[tex]\[
\text{Moles of H} = 2 \times 0.01125 \, \text{moles} = 0.0225 \, \text{moles}
\][/tex]
- Calculate the mass of hydrogen using its molar mass:
[tex]\[
\text{Mass of H} = \text{Moles of H} \times \text{Molar mass of H} = 0.0225 \, \text{moles} \times 1.008 \, \text{g/mol} = 0.0227 \, \text{g}
\][/tex]
3. Calculate the mass of oxygen in the original substance:
- Given the total mass of the organic substance is 0.2475 g, the mass of oxygen can be calculated by subtracting the masses of carbon and hydrogen from the total mass:
[tex]\[
\text{Mass of O} = \text{Total mass of substance} - (\text{Mass of C} + \text{Mass of H}) = 0.2475 \, \text{g} - (0.135 \, \text{g} + 0.0227 \, \text{g}) = 0.2475 \, \text{g} - 0.1577 \, \text{g} = 0.0898 \, \text{g}
\][/tex]
4. Calculate the percentage composition of oxygen:
- Using the mass of oxygen, the percentage composition can be calculated as:
[tex]\[
\text{Percentage of O} = \left( \frac{\text{Mass of O}}{\text{Total mass of substance}} \right) \times 100 = \left( \frac{0.0898 \, \text{g}}{0.2475 \, \text{g}} \right) \times 100 \approx 36.27 \%
\][/tex]
So the final answer is approximately [tex]\(36.27\%\)[/tex], which closely matches option D. However, this does not exactly match any of the given options A, B, or C. Consequently, the provided options might contain an error or ambiguity.
