Samples of three different compounds were analyzed and the masses of each element were determined.
compound mass n
(g) mass o
(g)
a 5.6 3.2
b 3.5 8.0
c 1.4 4.0
if you were john dalton and had never heard of a mole, which of the following would you think were possible sets of formulas for the compounds a, b, and c, respectively?

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.