Find the mass in grams of carbon dioxide produced by burning 21.7 grams of ethane

Answer 1

Hello, Ayah,

Start with a balanced equation. If this is where you needed help, I can be more specific on the steps - just let me know.

I come up with

2C₂H₆+7O₂→4CO₂+6H₂O

We want to know how much CO₂ is produced, in grams. But we need to start with moles. Find the number of moles of ethane by dividing the mass by ethane's molar mass. I get 0.721 moles ethane.

We know from the balanced equation that we'll get 4 moles of CO₂ for every 2 moles of C₂H₆. The molar ratio is 4 moles CO₂/2 moles C₂H₆, or 2:1. We should therefore expect to obtain 2*(0.7209 moles C2H6) or 1.442 moles CO₂. Convert this into grams CO₂ by multiplying by the molar mass of CO₂. We'd expect 63.4 grams of CO₂, to 3 sig figs.

Bob