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. We do as follows:
2.11x 10^24 atoms ( 1 mol / 6.022x10^23 atoms ) ( 32.06 g / 1 mol ) = 112.33 g sulfur
Hope this answers the question.