1. Find the molar mass of Al₂S₃:

* Aluminum (Al) has a molar mass of 26.98 g/mol.

* Sulfur (S) has a molar mass of 32.07 g/mol.

* Al₂S₃ has 2 aluminum atoms and 3 sulfur atoms.

* Molar mass of Al₂S₃ = (2 * 26.98 g/mol) + (3 * 32.07 g/mol) = 150.17 g/mol

2. Use the formula: moles = mass / molar mass

* moles = 510 g / 150.17 g/mol

* moles ≈ 3.40 mol

Therefore, there are approximately 3.40 moles in 510 g of Al₂S₃.