C2H6 + 7O2 = 4 CO2 + 6 H2O If you wanted to produce 5.83 moles of carbon dioxide, how many moles of oxygen would you needed to have started with?

Question

Grateful for any help given!

Answer 1

Hello, Kitty,

C₂H₆ + 7O₂ = 4 CO₂ + 6 H₂O

This equation has a conversion factor built in:

7O₂ = 4 CO₂, or

1 = 7O₂/4CO₂

(5.83 moles CO₂)* ( 7O₂/4CO₂) = 40.8 moles O₂

It takes 40.8 moles of oxygen to produce 5.83 moles of CO₂.

Bob

Answer 2

the balanced chemical equation here is

2C2​H6​(g) + 7O2​(g) → 4CO2​(g) + 6H2​O(g)

meaning that the molar ratio between oxygen and carbon dioxide is 7:4

so you can take the given value of 5.83 moles CO2 and then use the ratio to convert it over into moles of oxygen!

5.83 moles CO2 x 7 moles O2 / 4 moles CO2 = 10.2025 moles O2

so you would need 10.20 moles of O2 to produce 5.83 moles of CO2