Question

1.61gm Na2So4.10H2O contains same number of oxygen atom as present in x gram of H2SO4. Find x.

Answer 1

Number of mole of Na₂SO₄.10H₂O = given weight/molecular weight
= 1.61 gm/(46 + 32 + 64 + 180)
= 1.61/322gm/mol
= 0.005

∵1 mole of Na₂SO₄.10H₂O contains 14 moles of Oxygen atoms
∴ 0.005 mole of Na₂SO₄.10H₂O contains 14 × 0.005 = 0.07 mole of oxygen atoms.

Now, number of moles of oxygen= weight/atomic weight
⇒0.07 × atomic weight = weight
⇒0.07 × 16 = weight
⇒ weight = 1.12g

Hence, answer is 1.12 g