How do you calculate the number of grams in 1.023 moles?

1 Answer
Sep 22, 2016


You have specified a molar quantity; you have NOT specified a molar mass.


#1.023*"moles"# specifies #1.023xxN_A# individual items of stuff where #N_A="Avogadro's Number"=6.022xx10^23mol^-1#. #N_A# has the property that #N_Axx""^1H" atoms"# has a mass of #1*g# precisely!

Given a Periodic Table, we can immediately quote the molar mass of a given atom or molecule simply by summing up the individual molar masses. However, you have not specified what constitutes your molar quantity; it could be hydrogen atoms or molecules or nitrogens or methane molecules or something. So while we know the NUMBER of particles, we do not know the IDENTITY of the particles.