1. Determine the Chemical Formula
Aluminum sulfide is composed of aluminum (Al) and sulfur (S). The chemical formula for aluminum sulfide is Al₂S₃.
2. Calculate the Molar Mass
* The molar mass of aluminum (Al) is 26.98 g/mol.
* The molar mass of sulfur (S) is 32.07 g/mol.
The molar mass of Al₂S₃ is: (2 * 26.98 g/mol) + (3 * 32.07 g/mol) = 150.17 g/mol
3. Calculate the Number of Moles
* We have a 100 g sample of Al₂S₃.
* Divide the sample mass by the molar mass to get the number of moles: 100 g / 150.17 g/mol = 0.666 moles of Al₂S₃.
4. Calculate the Number of Aluminum Atoms
* Each mole of Al₂S₃ contains 2 moles of aluminum atoms.
* Multiply the number of moles of Al₂S₃ by 2 to get the number of moles of aluminum: 0.666 moles * 2 = 1.332 moles of aluminum.
* Use Avogadro's number (6.022 x 10²³ atoms/mol) to convert moles of aluminum to the number of atoms: 1.332 moles * 6.022 x 10²³ atoms/mol = 8.02 x 10²³ atoms of aluminum.
Therefore, there are approximately 8.02 x 10²³ aluminum atoms in a 100 g sample of aluminum sulfide.
