# Question 6a1e0

Dec 4, 2017

#### Answer:

$6.8 \cdot {10}^{- 5}$

#### Explanation:

The thing to remember here is that in order to have $1$ mole of xenon difluoride, you need to have $6.022 \cdot {10}^{23}$ 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 $6.022 \cdot {10}^{23}$ 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.