“I take it that you have never taken a quantitative analysis class. The 35.453 is the most important number because if you have one mole of chlorine gas, it will weigh 70.906 grams. Not 70 grams. Not 74 grams. But 70.906 grams.”
Yep sure have. Have you ever had to determine that number experimentally? It’s quite revealing.
How did you go about doing it? Did you count the number of molecules?