Question

what happen when butane undergo complete confusion

Answer 1

it forms blue flame and it's smokeless

Answer 2

I need to write an equation for the incomplete combustion of butane to form a mixture of carbon monoxide, unburnt carbon and water. If I do exactly as problem says I guess it should look like that:
C4H10 + 3O2 = CO + 3C + 5H2O
I'm a bit confused... Aren't I supposed to add carbon dioxide too even though in the problem it's not mentioned as a product?

Thanks!