Chemical Formula of Sodium Sulfate is Na₂SO₄.
As we know, 1 mole of any substance contains 6.022 × 10²³ particles. So, 1 mole of Na₂SO₄ also contains 6.022 × 10²³ formula units of Na₂SO₄.
Also,
1 mole of Na₂SO₄ contains = 6.022 × 10²³ Atoms of S
So,
4.5 moles of Na₂SO₄ will contain = X atoms of S
Solving for X,
X = (4.5 moles × 6.022 × 10²³ Atoms) ÷ 1 mole
X = 2.70 × 10²⁴ Atoms of S
Result:
4.5 Moles of Na₂SO₄ contains 2.70 × 10²⁴ Atoms of Sulfur.