Task

To model sulfuric acid production, 24 g of pyrite (FeS₂) was completely roasted in excess air. The sulfur(IV) oxide formed was oxidised by oxygen over a catalyst (80 % yield), and the sulfur(VI) oxide obtained was completely absorbed in 100 g of 9.8 % sulfuric acid. 1) Balance the roasting of pyrite by electron balance; calculate the volume of SO₂ (L, STP), the mass of the solid product and the volume of oxygen consumed. 2) Write the oxidation of SO₂ with conditions, show how to shift the equilibrium towards the product and find the mass of SO₃ obtained. 3) Write the absorption of SO₃ and calculate the mass fraction (%) of sulfuric acid in the resulting solution. Explain why industry absorbs SO₃ in concentrated sulfuric acid rather than water. For every part, show the method (reaction equations, formulas, reasoning) and all calculations step by step.