How many grams are in 8.2x10^22 molecules of n2i6?

Avogadro's number represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles.

 8.2x10^22 molecules ( 1 mol / 6.022 x 10^23 molecules ) ( 789.44 g / 1 mol ) = 107.50 grams N2I6