Question

Which of the following species has the largest mass percent of oxygen?

A. H2O
B. CaCO3
C. CO2
D. HCO3-

Answer 1

The species with the largest mass percent of oxygen is CaCO3 (option B). Calcium carbonate contains three oxygen atoms per molecule, giving it a higher mass percent of oxygen compared to the other options.

Step-by-step explanation:

The species with the largest mass percent of oxygen is CaCO3 (option B).

Calcium carbonate (CaCO3) contains three oxygen atoms per molecule, giving it a higher mass percent of oxygen compared to the other options.

In order to calculate the mass percent of oxygen for each option, you would need to determine the molar mass and mass of the oxygen atoms in each compound.

For example:

1. CaCO3: Molar mass = 40.08 g/mol (Ca) + 12.01 g/mol (C) + 3(16.00 g/mol) (O) = 100.09 g/mol
   Mass of oxygen (O) = 3(16.00 g/mol) = 48.00 g/mol
   Mass percent of oxygen = (48.00 g/mol / 100.09 g/mol) x 100% = 47.97%
2. H2O: Molar mass = 2(1.008 g/mol) (H) + 16.00 g/mol (O) = 18.02 g/mol
   Mass of oxygen (O) = 16.00 g/mol
   Mass percent of oxygen = (16.00 g/mol / 18.02 g/mol) x 100% = 88.91%
3. CO2: Molar mass = 12.01 g/mol (C) + 2(16.00 g/mol) (O) = 44.01 g/mol
   Mass of oxygen (O) = 2(16.00 g/mol) = 32.00 g/mol
   Mass percent of oxygen = (32.00 g/mol / 44.01 g/mol) x 100% = 72.71%
4. HCO3-: Molar mass = 1.008 g/mol (H) + 12.01 g/mol (C) + 3(16.00 g/mol) (O) = 61.02 g/mol
   Mass of oxygen (O) = 3(16.00 g/mol) = 48.00 g/mol
   Mass percent of oxygen = (48.00 g/mol / 61.02 g/mol) x 100% = 78.67%

Therefore, option B. CaCO3 has the largest mass percent of oxygen, which is approximately 47.97%.