Answer:
1.2×10^7 dm³
Explanation:
1 mole of sulfur dioxide weighs 64 grams, so 64 tonnes is 10^6 moles.
The reaction of interest is ...
2SO₂ +O₂ ⇆ 2SO₃
This reaction uses half as many moles of oxygen as of sulfur dioxide. That is, 5×10^5 moles of oxygen are required. That quantity will have a volume of ...
(5×10^5 mol)(24 dm³/mol) = 1.2×10^7 dm³ . . . volume of oxygen needed
