Chemistry

Percent composition by element

Element  Symbol  Atomic Mass  # of Atoms  Mass Percent

Barium    Ba         137.327              1              52.548%

Nitrogen  N           14.0067              2             10.719%

Oxygen   O           15.9994              6              36.733%

 

1 mole = 6.02 x 10^23 atoms.

10.719% x [6.02 x 10^23] =6.452838 x 10^22 atoms of Nitrogen in Barium Nitrate.

5.66 x [6.452838 x 10^22] =3.65 x 10^23 atoms of Nitrogen in 5.66 moles of Barium Nitrate.

CORRECTION: Sorry, I calculated the number of N atoms in 5.66 moles of Barium Nitrate.

If you want the number of moles of N, then just multiply:

10.719% x 5.66 =0.607 moles of N atoms in 5.66 moles of Barium Nitrate.

There are TWO 'N' atoms in each molecule, so 

 

 

5.66 moles x 2 atoms/molecule = 11.32 moles of 'N'