Which of the following compounds has the highest mass percent of oxygen?

• A. CO2
• B. H2O2
• C. C2H5OH
• D. H2O

Answer: (B)

Verified step by step guidance

1. Step 1: Understand that the mass percent of oxygen in a compound is calculated by dividing the total mass of oxygen atoms in one mole of the compound by the molar mass of the entire compound, then multiplying by 100%. The formula is: \(\text{Mass \% of O} = \frac{\text{Mass of O in 1 mole}}{\text{Molar mass of compound}} \times 100\%\).
2. Step 2: Calculate the molar mass of each compound by summing the atomic masses of all atoms present. Use atomic masses approximately: O = 16 g/mol, C = 12 g/mol, H = 1 g/mol.
3. Step 3: For each compound, determine the total mass of oxygen atoms by multiplying the number of oxygen atoms by 16 g/mol.
4. Step 4: Apply the mass percent formula for each compound: divide the total oxygen mass by the molar mass of the compound and multiply by 100%.
5. Step 5: Compare the calculated mass percents of oxygen for all compounds to identify which one has the highest value.