Question

If you are given a sample containg 1.204 x 10 24 molecules of NaCl, what is its weight in grams?

Answer 1

since 1 mole has 6.02*10^23 molecules, and mass of 58.45g, you have

12.04/6.02 * 58.45 = 116.9 g

that's 2 moles