Post-Module Question

[Jack Van Ryan 1A]

339.20 g of a cobalt metal is reacted with fluorine gas to produce 996.08 g of a compound. What is the empirical formula of the new compound?

Molar Mass: Co (58.93 g/mol); F (19.00 g/mol)

I got Co5F30, but I'm not sure if that's correct.

Thank you!

[Abhinav Amanaganti 3K]

The empirical formula is the most simple ratio of atoms of an element within a molecule, so Co5F30 would be a molecular formula because it gives the EXACT number of atoms of an element in the given compound. However, the empirical formula would be the most reduced ratio so it should be CoF6.

[emily3L]

After you find the mass percent of Co and Fe in the compound in grams, convert them to moles, divide by the smallest amount, and multiply by the smallest factor to get a whole number, Co5F30 is correct.

[Ruben Adamov 1E]

If you want the empirical formula the simplest form is required. For example your answer was Co5 F30. The correct answer in this case would be CoF6 as that is the simplest form.

[Elizabeth Kim 2K]

Co5 F30 would be the molecular formula for this example. To find the empirical formula, you would need to divide by the smallest amount of moles in order to find the simplest ratio of atoms in the molecule. Once you simplify the molecular formula, you should end up with CoF6 as the empirical formula. Hope this helps!