This is a mole

Our moles are a little different. We mean the "gram molecular weight" which is just the molecular weight in grams. In order to get the molecular weight you need the chemical formula of the contaminant. For carbon monoxide, the formula is CO which means each molecule of carbon monoxide has one atom of carbon and one atom of oxygen.

Next we look up the atomic weights of carbon and oxygen. They are inside the front or back cover of your (almost any) chemistry book. You will find 12 for carbon and 16 for oxygen. (Actually your book probably says 12.011 for carbon and 15.9994 for oxygen, but 12 and 16 is close enough). So the molecular weight for CO is just 12 + 16 which equals 28.

Finally so the molecular weight in grams is 28 gm and we say a mole of CO is (or weighs) 28 gm. BACK