What chemical makes smokey breath white?

Answer 1

It depends on what smokey breath you are talking about. Are you talking about cigarette white smoke? Or are you talking about white breath when you exhale in cold weather?

If it's cigarette smoke, it's usually the burning of the paper which creates the smoke. Cigarette manufacturers attempted in the late 80's and early 90's to make a "smokeless" cigarette, but consumers (smokers) didn't like the "taste" of the smokeless cigarettes.

If it's white "smokey" breath when breathing in cold weather, the chemical is water vapor. You have to remember that humidity is "relative". Warmer air can hold more water than colder air. So, when the warm air from your airways meets the cold air you're breathing out to, the water in the warm air precipitates out... because the colder air can no longer hold the water. Thus, the white breath. (It's basically the same reaction as rain and fog, warm air hits cold front).

Hope that answers your question. You can probably do a Wiki Search on "Relative Humidity".