Do you have a sample of 5.6 g of ethene, C2H4 and completely react with the oxygen in the air? How many moles of carbon dioxide and what mass of water is obtained?

Answer 1

C₂H₄ + 3O₂ ==> 2CO₂(g) + 2H₂O ... balanced equation

NOTE: for every 1 mole of C₂H₄ you can produce 2 moles CO₂ and 2 moles H₂O assuming O2 is NOT limiting

moles C₂H₄ used = 5.6 g x 1 mole/28 g = 0.20 moles

moles CO₂ produced = 0.20 moles C₂H₄ x 2 moles CO₂/mole C₂H₄ = 0.40 moles CO₂

mass H₂O produced = 0.20 moles C₂H₄ x 2 moles H₂O/mole C₂H₄ x 18 g/mole = 7.2 g H₂O