When the Catholic Church and Science Get Along

I asked myself yesterday, while watching TV, what is used to make the papal smoke turn either white or black, and how do they make sure there is no false alarm.  In my research I found that they previously used wet straw to make the black smoke and nothing added to make the white smoke. But in an article by The Guardian, I found that they now use an electronic smoke machine, starting in 2005, where potassium perchlorate (KClO₄), anthracene (3 fused benzene rings), and sulphur is used to make the black smoke, while potassium chlorate (KClO₃), lactose and a pine resin is used to make the white smoke.

So how does this work?

Black
The anthracene (from tar) helps the burnt carbon from the paper flow upwards in the smoke instead of remaining in the ash.  The KClO₄ is used to aide the combustion of the paper to create the chunks of carbon. What carries all of this upward is the water that is generated in the chemical reaction of combustion. Just think of it as the burnt carbon as being graphite, which produces a back colour.

White
What creates the white smoke is the existence of unburnt paper, or other unburnt fuel, rising up with the heat.  The paper is thermally broken apart in a process called pyrolisis, leaving small white particles of unburnt cellulose, or from the added resin, rising up as the combustion product of H₂O rises out of the chimney. Just think of the particles of unburnt fuel being like table sugar, which gives off a white colour.

References:
Via: The Guardian