How do you convert .4190 moles of oxygen difluoride to particles of oxygen difluoride?
You use Avogadro's constant!
You can go from moles of oxygen difluoride,
Avogadro's constant is basically the definition of the mole. In this case, you know for a fact that in order to have
Since your sample contains a little under
More specifically, your sample will contain
#0.4190 color(red)(cancel(color(black)("moles OF"_2))) * overbrace((6.022 * 10^(23)color(white)(.)"molecules OF"_2)/(1color(red)(cancel(color(black)("mole OF"_2)))))^(color(blue)("Avogadro's constant"))#
# = color(darkgreen)(ul(color(black)(2.523 * 10^(23)color(white)(.)"molecules OF"_2)))#
The answer is rounded to four sig figs, the number of sig figs you have for the number of moles of oxygen difluoride.