To find out how many moles are in 4.15 g of silicon (Si), you can use the formula:
Number of moles = Mass (g) / Molar mass (g/mol)
First, find the molar mass of silicon. The molar mass of silicon is approximately 28.09 g/mol. Now, plug in the values:
Number of moles = 4.15 g / 28.09 g/mol
Calculating this gives:
Number of moles ≈ 0.147 moles
Therefore, there are approximately 0.147 moles of silicon in 4.15 g.