To calculate the number of oxygen atoms and the mass of oxygen in 5g of calcium carbonate (CaCO3), we need to consider the molar mass and the chemical formula of calcium carbonate.
The molar mass of calcium carbonate (CaCO3) can be calculated by adding up the atomic masses of its constituent elements:
Molar mass of CaCO3 = (molar mass of Ca) + (molar mass of C) + 3 * (molar mass of O)
The atomic masses of the elements involved are approximately:
- Calcium (Ca) = 40.08 g/mol
- Carbon (C) = 12.01 g/mol
- Oxygen (O) = 16.00 g/mol
Molar mass of CaCO3 = 40.08 g/mol + 12.01 g/mol + 3 * (16.00 g/mol) = 100.09 g/mol
Now we can use the molar mass of CaCO3 to determine the number of moles of calcium carbonate in 5g:
Number of moles = Mass / Molar mass Number of moles = 5g / 100.09 g/mol = 0.04996 mol (approximately)
According to the chemical formula of calcium carbonate (CaCO3), there is one oxygen atom for each carbonate group (CO3). So, in 0.04996 mol of calcium carbonate, the number of moles of oxygen atoms is also 0.04996 mol.
To calculate the number of oxygen atoms, we can use Avogadro's number (N_A), which is approximately 6.022 × 10^23 atoms/mol:
Number of oxygen atoms = Number of moles * Avogadro's number Number of oxygen atoms = 0.04996 mol * 6.022 × 10^23 atoms/mol ≈ 3.003 × 10^22 atoms
Finally, to determine the mass of oxygen in 5g of calcium carbonate, we multiply the number of moles of oxygen by its molar mass:
Mass of oxygen = Number of moles * Molar mass of O Mass of oxygen = 0.04996 mol * 16.00 g/mol = 0.7994 g (approximately)
Therefore, in 5g of calcium carbonate, there are approximately 3.003 × 10^22 oxygen atoms, and the mass of oxygen is approximately 0.7994 g.