Question

Question #a348e

Answer 1

`9.022 * 10^23` atoms

Explanation:

As you can infer from the formula, one `Na_2CO_3` molecule contains 2 atoms of sodium, 1 atom of carbon, and 3 molecules of oxygen. You can use this as a conversion factor, therefore, to infer that for every mole of `Na_2CO_3` you have, you will have 3 moles of oxygen.

However, you don't have `1` mol of `Na_2CO_3`, you have `0.5`. However, this is easily remedied using a simple conversion factor:

`0.5 cancel(" mol " Na_2CO_3) * ("3 mol oxygen")/("1" cancel("mol" Na_2CO_3)) = 1.5 "mol oxygen"`

However, we're not done yet! We have 1.5 moles of oxygen, not atoms. However, we do know that `"1 mole" = 6.022 * 10^23` atoms. Hence, we can use that as another conversion factor:

`1.5 cancel(" mol oxygen") * (6.022* 10^23 " atoms of oxygen")/cancel(1 " mol oxygen")`

This leaves `9.022 * 10^23` atoms of oxygen.

If you need more help on converting between moles and atoms and mass, here's some useful resources:

Handy Graphic:

Really useful video:

Hope that helped :)