How many atoms are present in 1.25g of molecular hydrogen? I know the way to do it..but for molar mass, would it be 2.02g or 1.00g?
The molar mass of H2 is 2.02 grams
1.25/2.02 is the number of moles of H2
multiply the number of moles of H2 by Avogadro's number, and you have the number of molecules of H2
multiply the number of molecules of H2 by 2 and you have the number of atoms of H