How many grams of carbon dioxide will be formed when 100. grams of C4H10 is burned in oxygen?

Answer 1

Hello, Omran,

We need to start with a balanced equation. The combustion of hexane is slightly more challenging, since although we can start with one molecule of C4H10 and one molecule of O2, to see what happens, we find that the two products, CO2 and H2O require that we have more than two oxygen atoms. We need three O atoms, but since oxygen can only exist in a diatomic state, as we increase the O2 number we run out of C or H atoms. So we need to increase the C₄H₁₀ coefficient by at least 1. It winds up taking 2 molecules of butane before we have a "legally" balanced equation:

2C₄H₁₀ + 13O₂ = 8CO₂ + 10H₂O

From this we can see that we form 8 moles of CO₂ for every 4 moles C₄H₁₀. Next, calculate how many moles of C₄H₁₀ we have in 100 grams of the compound. We need the molar masses of both the butane and carbon dioxide (I used 58.1 and 44.0 g/mole, respectively). We have 100g/(58.1g/mole) = 1.72 moles of butane.

Multiply the moles of butane by the molar ratio of CO₂/C₄H₁₀ (4) to find out many moles of CO₂ are produced. If all the butane is combusted (we have plenty of O₂), we'll produce 6.88 moles of CO₂. Convert that to grams using the molar mass of CO₂. (6.88moles CO₂)*(44.0g CO₂/mole CO₂) = 303 grams CO₂.

Fun, but a waste of butane and we add to global warming.

I hope this helps,

Bob