In the combustion of hydrocarbon, carbon monoxide is formed. What has occurred?

1 Answer
anor277
Apr 24, 2016

Incomplete combustion.

Explanation:

In circumstances where there is insufficient dioxygen gas, incomplete combustion of hydrocarbons to give #CO# gas and #C# as soot can occur. This typically occurs in internal combustion engines and (more so) in diesel engines.

Complete combustion of hexanes may be represented by an equation:

#C_6H_14(l) + 19/2O_2(g) rarr 6CO_2(g) + 7H_2O(l)#

If some of the hexanes were incompletely combusted I could write:

#C_6H_14(l) + 9O_2(g) rarr 5CO_2(g) + CO(g) + 7H_2O(l)# OR

#C_6H_14(l) + 8O_2(g) rarr 4CO_2(g) + CO(g) + C(s) + 7H_2O(l)#

Longer chain hydrocarbons (such as diesels) typically burn dirty. How do I know that 1 mole of soot or carbon monoxide were produced in the given equations? Of course, I don't know that, but I know there were SOME products of incomplete combustion, and I modified the complete combustion to represent this. A typical internal combustion engine (or a furnace or a diesel engine) is designed to permit some incomplete combustion.

Related questions
See all questions in Redox Reactions
Impact of this question
5412 views around the world
You can reuse this answer
Creative Commons License