I need help studying molar mass?

Question

I am confused, does the atomic mass represent the weight in grams of 6.022*10^23 atoms of a certain element. If so then how did they make the number that accurate that the number of protons and neutrons times 6.022*10^23 is the weight in grams

Answer 1

A molar mass is 6.023*10^23, it can be in any units you want it in. It can be on Kg/kmol, g/mol, lb/mols...anything

Answer 2

Yes, the atomic weight of an element is equal to the weight in grams of one mole of atoms of that element. So for example, if you look at a periodic  table, it says the atomic weight for Li is 6.941 which means 6.941 atomic mass units(amu) and that is equal to 6.941 grams so a mole of Lithium atoms would have a mass of 6.941 grams.

Note that the atomic mass given on the periodic table is an average of the masses of all the stable isotopes of an element taking into consideration their relative abundance so that mass would be more true for a natural sample of atoms of that element. For example, if you had a mole of pure Lithium-6 atoms, it would not have a mass of 6.941 grams however if you found one mole lithium somewhere, that is, if you found a naturally occurring sample lithium it's mass would be about 6.941 grams per mole.

I don't know the answer to your second question about how such a precise value for avogrado's number was obtained. I know the methods but I assume you're not asking about the methods because you could easily find that online. I don't know the details of how the value was obtained though, just the methods used.  

Answer 3

Since the time Cannizzaro expounded a system of atomic

weight determination in the Karlsruhe Congress in 1860

and firmly established Avogadro hypothesis, there

have been dozens of experimental methods for determining

the Avogadro number.  

The value was 6.022045x10^23 mol^-1 when I went to school.

The mass of the protons, neutrons and electrons does not equal the amu of an element. Combining these components to form an atom gives off a tremendous amout of energy, and Einstein's famous relationship between mass and energy is E = mc^2

Answer 4

A mole of anything will be Avogadros number. Say you have a mole of pencils and a mole of paper which would you have more of? There the same amount because a mole is a mole.