I am trying to figure out how many atoms are in 4.2 moles of BaO. I took 4.2 moles and multiplied it by 1/109.32, resulting in .038. Is this correct? Thanks hopefully this will be the final one.
No.
There are 6.02 x 10^23 molecules in 1 mole of anything. You have 4.2 moles BaO; therefore, there will be 6.02 x 10^23 x 4.2 = ?? molecules BaO. Since there are two atoms per molecule BaO, you will have twice that many atoms.
I saw your question that Bob Pursley answered. You haven't caught the concept I don't believe.
25.284 x 10^23 atoms?
(6.02 x 10^23 molecules BaO/1 mole BaO)x (4.2 moles BaO) x (2 atoms/1 molecule) = ?? and I don't get 25 something.
To determine the number of atoms in a given number of moles, you need to use Avogadro's number, which is approximately 6.022 x 10^23 atoms per mole.
To calculate the number of atoms in 4.2 moles of BaO, you would multiply 4.2 moles by Avogadro's number.
4.2 moles * (6.022 x 10^23 atoms/mole) = 2.52764 x 10^24 atoms
Therefore, there are approximately 2.53 x 10^24 atoms in 4.2 moles of BaO.
It appears that your calculation is incorrect. You should multiply the number of moles (4.2) by Avogadro's number (6.022 x 10^23) to get the correct result.