How many ATOMS of sulfur are present in 2.05 moles of sulfur dichloride?

Answer 1

First write the chemical formula for sulfur dichloride.

That would be SCl₂ meaning for each molecule of sulfur dichloride there is one atom of sulfur.

In 1 mole of anything there are 6.022 x 10²³ items (that's Avogadro's number). So in 2.05 moles of SCl₂, there are (2.05)(6.022 x 10²³) = 1.23 x 10²⁴ molecules and since there is one atom of sulfur in each, then there are 1.23 x 10²⁴ atoms of sulfur present.