What is the mass percent of carbon in oxalic acid (C2H2O4)?

• A. 12.0%
• B. 26.7%
• C. 40.0%
• D. 53.3%

Answer: (B)

Verified step by step guidance

1. Identify the molecular formula of oxalic acid, which is C\_2H\_2O\_4.
2. Calculate the molar mass of oxalic acid by summing the atomic masses of all atoms: multiply the atomic mass of carbon (C) by 2, hydrogen (H) by 2, and oxygen (O) by 4, then add these values together. Use atomic masses approximately as C = 12.0 g/mol, H = 1.0 g/mol, and O = 16.0 g/mol.
3. Calculate the total mass of carbon in one mole of oxalic acid by multiplying the number of carbon atoms (2) by the atomic mass of carbon (12.0 g/mol).
4. Use the formula for mass percent: \(\text{Mass percent of C} = \left( \frac{\text{mass of C in the compound}}{\text{molar mass of the compound}} \right) \times 100\%\).
5. Substitute the values calculated for the mass of carbon and the molar mass of oxalic acid into the formula to find the mass percent of carbon.