I use what is called the picket fence method to convert from moles to molar mass.
Moles is measured in moles while molar mass is measured in grams.
If you are given moles in the problem, then you want to multiply that by the ratio of molar mass to moles. Molar mass is how much mass of a sample of that compound divided by the amount of substance in the sample.
Example: 12.01 g Carbon = 1 mole of Carbon
We have 3 moles of carbon. Therefore, we have 36.03 grams of carbon.
3 moles carbon × (12.01 g carbon / 1 mole carbon) = 36.03 g carbon
