Question

What is the mole ratio of `Fe_3O_4` to `Fe`?

Answer 1

Suppose instead I had a dozen formula units of `Fe_3O_4`...

Explanation:

I think that by using simple arithmetic you should very quickly be able to tell me that I had 36 iron atoms, and 48 oxygen atoms....do you agree?

Here we have a `"mole"` of `Fe_3O_4` units, i.e. a mass of `231.4*g`...but a mole specifies Avogadro's number of particles....we write `N_A=6.022xx10^23*mol^-1`.. And so we can use the `"mole"` as a collective number precisely as we do the `"dozen"`.

And so we gots `1*mol` `Fe_3O_4`...we gots `3*mol` of iron atoms, and `4*mol` of oxygen atoms...

If I got one mole of `P_4O_10`, can you tell me the numbers and the masses of the constituent atoms?