Chemistry stoic

Question

How many grams of sulfur trioxide will be made when 18.7 L of oxygen react with excess sulfur.

2S + 3O₂ → 2SO₃

 

Answer 1

Write a correctly balanced equation for the reaction taking place:

2S + 3O₂ ==> 2SO₃

Assuming the reaction takes place at STP (standard temperature and pressure), we can calculate the moles of O₂ present as 18.7 L x 1 mol/22.4 L = 0.835 moles O₂ present

mass SO₃ theoretically produced = 0.835 mol O₂ x 2 mol SO₃/3 mol O₂ x 80 g/mol SO₃ = 44.5 g SO₃