Burning acetylene in oxygen can produce three different carbon-containing products: soot (very fine particles of graphite), CO(g), and CO₂(g). (c) Why, when the oxygen supply is adequate, is CO₂(g) the predominant carbon-containing product of the combustion of acetylene?

Video transcript

Hey everyone. The question here states the combustion of hydrocarbons can produce soot, carbon monoxide and carbon dioxide, which of the following statements is correct. So before we look at our answer choices, let's go ahead and think about a combustion reaction. For example, let's use methane and we react this with oxygen. When we do this, we have a combustion reaction where we produce carbon dioxide and water vapor. And to balance this out, we would need to add a two prior to our water and a two prior to our oxygen gas. So let's go ahead and look at our answer choices when comparing these. We can see that we have a difference here in our product of combustion, we have carbon monoxide for C and C for D. Since we already wrote out our combustion reaction, we can eliminate cnd since we know that we produce carbon dioxide. Now, let's go ahead and choose the right answer. When there is excess oxygen, the predominant product of combustion is carbon dioxide because oxygen or carbon is completely oxidized. So let's think about this. So looking at our reaction For oxygen, we see that our oxidation state goes from a zero two, a negative two. So this means it gets reduced and we also know that oxygen is a great oxidizing agent. And since we know this, that means we can eliminate a so our answer here is going to be be because when there is excess oxygen, the predominant product of combustion is carbon dioxide because carbon is completely oxidized and we know this is correct because carbon does gain electrons through those oxygen's. So I hope this made sense and let us know if you have any questions.