Stoichiometry In chem 1215

Question

Sulfurous acid is unstable in aqueous solution and gradually decomposes to water and sulfur dioxide gas

H2SO3–>H2O+ SO2

if 3.25g of sulfurous acid undergoes this reaction what mass of sulfur dioxide is released?

Answer 1

H₂SO₃ ==> H₂O+ SO₂ ... balanced equation

molar mass H2SO3 = 82.08 g/mol

3.25 g H₂SO₃ x 1 mol H₂SO₃ / 82.08 g = 0.039596 moles H₂SO₃

0.039596 molesH₂SO₃ x 1 mol SO₂ / 1 mol H₂SO₃ = 0.039596 moles SO₂

molar mass SO₂ = 64.1 g/mol

grams SO₂ = 0.039596 moles SO₂ x 64.1 g/mol = 2.54 g (3 sig. figs.)