Final answer:
The percentage by mass of oxygen in copper trioxocarbonate (V), also known as copper carbonate (CuCO3), is approximately 38.85%.
Step-by-step explanation:
To find the percentage by mass of oxygen in copper trioxocarbonate (V), we need to know the chemical formula of the compound. Copper trioxocarbonate (V) is also known as copper carbonate or CuCO3. The molar mass of CuCO3 can be calculated by adding up the atomic masses of its constituent elements: Cu (copper) with a molar mass of 63.55 g/mol, C (carbon) with a molar mass of 12.01 g/mol, and O (oxygen) with a molar mass of 16.00 g/mol. Therefore, the molar mass of CuCO3 is 63.55 g/mol + 12.01 g/mol + (3 x 16.00 g/mol) = 123.55 g/mol.
The mass of oxygen in CuCO3 can be calculated by multiplying the molar mass of oxygen by the number of oxygen atoms in the compound. In CuCO3, there are 3 oxygen atoms, so the mass of oxygen is 3 x 16.00 g/mol = 48.00 g/mol.
To find the percentage by mass of oxygen in CuCO3, divide the mass of oxygen by the molar mass of CuCO3 and multiply by 100%. Therefore, the percentage by mass of oxygen in copper trioxocarbonate (V) is (48.00 g/mol / 123.55 g/mol) x 100% ≈ 38.85%.