This whole unit thing of mols is somewhat tricky and interesting. if one mol of Na is 23g, then wouldnt 100.3g of NaCl be one Mol as well. I am under the impression from my lecture notes in class that the grams of a substance is the same a s a mol. I was asked a school of thought question by the profesor. How many mols is in 100.3g of NaCl. I said one because the notes stated that the grams of the substance is also equal to one mol. But as i write this i am puttign things together. is it only one mol IF the grams of whatever happen to be equal to the amu. so NaCl has a molar mass of 58. if the question was asked, if you had 58g of NaCl, then that would be ONE mol right. it couldnt be the 100.3g is one mol because the 100.3g is not equal to the amu of NaCl thanks guys.