i don't understand how to do these two

Question

1. How many grams (g) will you need to make 480.0 mL of a 1.80 M NaOH solution?
2.  In the reaction below, how many moles of iron (Fe) are needed to form 6.4 moles of iron (III) oxide (Fe₂O₃)?  4 Fe + 3 O₂ →2 Fe₂O₃

Answer 1

M = n/L

mol NaOH = 40g

n = M X L= .1.8M X .48L = .864mol

.864mol NaOH X 40g NaOH/mol NaOH = 35gNaOH

6.4mol Fe2O3 X 4mol Fe/2mol Fe2O3 = 12.8mol Fe