Question

What is the mass of 12.04×10^24 molecules of ammonia?

Answer 1

MNH3 = 1.75 x 10^24 molecules x 1 mol/6.02 x 10^23 molecules x 17.03g/1mol
(cancel out molecules and mol; you'll be left with grams as units).

When you perform this calculation, you find out that the mass of 1.75 x 10^24 molecules of NH3 is: 49.5 grams.