11 posts • Page 1 of 1
Shanna Yu 3F wrote:Hi!
Someone can correct me if I'm wrong, but I believe combustion problems typically operate under the assumption that oxygen is in excess unless it's stated otherwise.
You're correct. Usually, it is assumed there is an excess of O2 in combustion reactions.
If there is no amount value given for O2, like the other replies say, you usually assume O2 is in excess in a combustion reaction. From what I have seen in this class so far, they usually tell us that the experiment is performed with an "excess of oxygen," so I don't think we have to worry about it too much!
The problem should always tell you when an excess reactant is present in a reaction. So then you'll have to work with the limiting reactant to solve whatever it is the problem is asking. Oxygen will very typically always be in excess since it is unusual, in the real world, to run out of oxygen in an environment for a combustion reaction. However, if they give you a certain number of moles of oxygen to work with, at that point, you should use your molar ratio knowledge to figure if it's the limiting reactant in that reaction.
Who is online
Users browsing this forum: No registered users and 1 guest