To determine the number of atoms of oxygen (O) in 10.0 g of C₂H₆O₂ (acetic acid), you'll need to follow these steps:
Find the molar mass of C₂H₆O₂:
- Carbon (C) has a molar mass of approximately 12.01 g/mol.
- Hydrogen (H) has a molar mass of approximately 1.01 g/mol.
- Oxygen (O) has a molar mass of approximately 16.00 g/mol.
The molar mass of C₂H₆O₂ can be calculated as follows: (2 * molar mass of C) + (6 * molar mass of H) + (2 * molar mass of O)
= (2 * 12.01 g/mol) + (6 * 1.01 g/mol) + (2 * 16.00 g/mol) = 24.02 g/mol + 6.06 g/mol + 32.00 g/mol = 62.08 g/mol
Calculate the number of moles of C₂H₆O₂ in 10.0 g: Number of moles = Mass / Molar mass Number of moles = 10.0 g / 62.08 g/mol Number of moles ≈ 0.161 mol
Determine the molar ratio between O atoms and C₂H₆O₂: From the chemical formula C₂H₆O₂, we can see that there are two oxygen atoms (O) in one molecule of C₂H₆O₂.
Calculate the number of O atoms in 0.161 mol of C₂H₆O₂: Number of O atoms = Number of moles of C₂H₆O₂ * (2 * Avogadro's number) Number of O atoms = 0.161 mol * (2 * 6.022 x 10^23) Number of O atoms ≈ 1.943 x 10^23
Therefore, there are approximately 1.943 x 10^23 oxygen atoms in 10.0 g of C₂H₆O₂.