What mass of excess reactant remains at the end of the reaction if 90.0 g of SO₂ are mixed with 100.0 g of O₂? 2SO₂ + O₂→ 2SO₃ A) 10.0 g B) 12.5 g C) 22.5 g D) 55.0 g E) 77.5 g

Question

Quizplus · Accepted Answer

The limiting reactant is SO₂. 90.0 g of SO₂ is 1.406 moles, and 100.0 g of O₂ is 3.125 moles. The reaction requires 1 mole of O₂ for every 2 moles of SO₂, so only 0.703 moles of O₂ are needed. Therefore, 3.125 - 0.703 = 2.422 moles of O₂ remain, which is 77.5 g.

What Mass of Excess Reactant Remains at the End of the Reaction