Answer:
b). 0.732
Explanation:
52g Na₂SO₄ x 1 mol Na₂SO₄ x 2 mol Na
------------------------- -------------------- = 0.732 mol Na
142.04 g Na₂SO₄ 1 mol Na₂SO₄
Atomic Mass Units
Na₂ = 22.99 x 2 = 45.98
S = 32.06
O₄ = 16 x 4 = 64
Na₂SO₄ = 45.98 + 32.06 + 64 = 142.04
There are 2 moles of Na in 1 mole of Na₂SO₄
