Questions: What is the mass percentage of O in C3H3O2? A 21.03% B 57.94% C 72.58% D 42.06%

Solution Steps

The compound is \(\mathrm{C}_{3} \mathrm{H}_{3} \mathrm{O}_{2}\). We need to find the molar mass of each element:

• Carbon (C): \(3 \times 12.01 \, \text{g/mol} = 36.03 \, \text{g/mol}\)
• Hydrogen (H): \(3 \times 1.008 \, \text{g/mol} = 3.024 \, \text{g/mol}\)
• Oxygen (O): \(2 \times 16.00 \, \text{g/mol} = 32.00 \, \text{g/mol}\)

Add the molar masses of all the elements to find the total molar mass of \(\mathrm{C}_{3} \mathrm{H}_{3} \mathrm{O}_{2}\): \[ 36.03 \, \text{g/mol} + 3.024 \, \text{g/mol} + 32.00 \, \text{g/mol} = 71.054 \, \text{g/mol} \]

The mass percentage of an element is given by the formula: \[ \text{Mass percentage of } O = \left( \frac{\text{Mass of } O}{\text{Total molar mass of the compound}} \right) \times 100\% \] Substitute the values: \[ \text{Mass percentage of } O = \left( \frac{32.00}{71.054} \right) \times 100\% \approx 45.02\% \]

Final Answer