Question

Convert 3.00 x 1020 N2 molecules to mass in grams.

Answer 1

$$n = N/N_a = 3.00*10^{20}/6.02*10^{23} = 0.50*10^{-3} mol$$

$$m = nM = 3.00*10^{-3}*28.00g/mol = 8.40*10^{-2} g$$