Question

Question #6a1e0

Answer 1

`6.8 * 10^(-5)`

Explanation:

The thing to remember here is that in order to have `1` mole of xenon difluoride, you need to have `6.022 * 10^(23)` molecules of xenon difluoride.

This number, which is known as Avogadro's constant, is essentially the definition of the mole. So `1` mole of a given substance will always contain `6.022 * 10^(23)` atoms/molecules/ions, whatever the case may be, of that substance.

You can thus say that your sample of xenon difluoride will be equivalent to

`4.1 * 10^(19) color(red)(cancel(color(black)("molecules XeF"_2))) * "1 mole XeF"_2/(6.022 * 10^(23)color(red)(cancel(color(black)("molecules XeF"_2)))) = color(darkgreen)(ul(color(black)(6.8 * 10^(-5)color(white)(.)"moles XeF"_2`

The answer is rounded to two sig figs, the number of sig figs you have for the number of molecules of xenon difluoride.