Aqueous sodium bisulfite gives off sulfur dioxide gas when heated, needed is moles and grams of different chemicals?

Question

Aqueous sodium bisulfite gives off sulfur dioxide gas when heated:

2NaHSO₃(aq) → Na₂SO₃(aq) + H₂O(ℓ) + SO₂(g)

If 567 mL of a 1.005 M NaHSO₃ solution were heated until all the NaHSO₃ had reacted, what would be the resulting concentration of the Na₂SO₃ solution? How many moles of SO₂ would be formed? How many grams of SO₂ would be formed? If each mole of SO₂ had a volume of 25.78 L, what volume of SO₂would be produced?

Answer 1

First we will use dimensional analysis to determine the number of moles of Na₂SO₃:

0.567 L (1.005 mol/1 L) ( 1 mol Na₂SO₃/2 mol NaHSO₃) = 0.285 mol Na₂SO₃.

To find the concentration, we will divide moles of Na₂SO₃ by the initial volume, assuming no volume is lost during the reaction:

0.285 mol Na₂SO₃/0.567 L = 0.503 M mol Na₂SO₃

To find the number of moles of SO₂, we will use dimensional analysis again:

0.567 L (1.005 mol/1 L) ( 1 mol SO₂/2 mol NaHSO₃) = 0.285 mol SO_2.

To find the grams, we will use the molecular weight:

0.285 mol SO₂ ( 64 g SO₂/ 1 mol SO₂) = 18.24 g SO₂

To determine the volume, use dimensional analysis with the new conversion ratio:

0.285 mol SO_2.(25.78 L/ 1 mol SO₂) = 7.347 L SO₂.