310tutoring shows viewers how to easily convert Grams to Moles for Chemistry. If you have 120 grams NaOH and we want this in moles we need a periodic table. Now, you need to figure out what the mass is of each individual element in NaOH. You need the mass of Na, O and H. Na mass is 23, O has 16 and H is 1. Add all of these up to get the molar mass of NaOH is 40 g/mol. Now use this to convert 120 g to moles. Now take 120 grams NaOh and multiply this by 1 mol NaOH/ 40 grams NaOH. You can cancel out the grams and you have moles left. Now you do 120 x 1 / 40 and you get 3 moles of NaOH! Now you can easily convert grams to moles.