Question

how many moles of silicon are in 245 g of silicon? a. 8.72 mol b. 28.0 mol c. 1.10 10-1 mol d. 6.90 103 mol

Answer 1

Atomic mass silicon = 28.085 u

1 mol Si ---------------- 28.085 g  
?  ------------------------ 245 g

245 x 1 / 28.085 => 8.72 mol

answer A