5 posts • Page 1 of 1
I'm confused about why the atomic masses on the periodic table are the amount of grams in a mole of that element. In other words, I know that the atomic masses are the molar masses for elements, but I don't understand why they are. What do the atomic masses, (which are in amu?) have to do with the amount of grams in a mole? I'm just having a hard time seeing what the connection between these two pieces on info is, like why are they the same number?
Honestly, I've been wondering the same thing. I always thought that atomic mass and molar mass were interchangeable, and that molar mass was usually used for when you needed to calculate the mass of a compound. For example, the atomic mass of C (carbon) is 12, but the molar mass for the molecule CO2 (carbon dioxide) is 44. This probably isn't the whole reason, but thought I'd just add what I think is a distinct differentiation between the two.
The problem with the whole thing is that scientists used 12.000 grams of carbon (diamond) to figure out how many atoms were in a mole. Grams are the best standard that we have, so scientists used that as a baseline measurement. Professor Caram said that scientists are currently trying to use a sphere of silicon to determine an exact weight to atoms ratio.
This was confusing for me as well. I looked back at the lecture notes and I have written down that the mass of sample (g) = number of moles (mol)*molar mass of element (g*mol^-1). I'm not sure if that helps or not?
Who is online
Users browsing this forum: No registered users and 2 guests