Science Buddies: "Ask an Expert"

I have been doing some background research on smoke bombs, and a very effective one can be made from simple household ingredients. These include, sugar (C6H12O6), salt peter (KNO3), and some recipes call for baking soda (NaHCO3). My question is what does this smoke bomb produce? Or more specifically, what compounds make up the smoke? I have difficulty determining the products, because the three ingredients above are melted together in a pot over low heat. I hope to use this information to produce a low cost fire suppression method, using the smoke to "choke" the fire. Thank you for your response!

Please provide some additional details:
1) What grade are you in?
2) Have you had chemistry yet?
3) Who are you working with? A teacher, a parent, somebody else?
4) Where are you planning to conduct your experiments?

Smoke bombs by their very nature are nasty things to be working with and tend to cause messes so there are probably much better projects to be spending your time on.

Commercial fire suppressant systems usually have a design criterion of trying to minimize the damage and this includes smoke damage.

o my apologies for not already posting this information:

I am in the tenth grade, and yes I have taken chemistry one honors, and am in the process of taking chemistry AP. I am still looking for a mentor, and just doing some background research as of now. I haven't really decided where i would conduct my experimentation, other than my home.

I understand that smoke damage is a problem, I have dealt with it in my home before, but I believe that first and foremost is the damage dealt by the fire, everything else is really secondary to that. I would really appreciate it if you would elaborate on "messy things". From my understanding, smoke bombs are simply that, they produce smoke, really nothing very messy about it.

Thank you again for your time.

If your project is to come up with a fire suppression method, you first need to understand fires and how fires are fought.

What are the three components that are required to sustain a fire? Take any one away and the fire goes out. Do some research.

I'm not sure how you intend to use smoke from one fire (smoke bomb) to put out another fire. Even if it were possible, smoke is a hazzard to people. Even if it were safe to breath the smoke from a smoke bomb, it obscures visibility which creates a safety hazzard.

If you are just curious about the chemical reactions in a sugar / KNO3 smoke bomb with a NaHCO3 retardant, it is a fairly simple oxidation reduction reaction that you should be able to work out yourself or do a little research and figure it out. The whole heating prepartion process is all about forming a uniform solid mixture with appropriate proportions so that it will burn slowly and uniformly at a temperature that will produce a lot of smoke. This process has nothing to do with the chemical reactions that happen when the smoke bomb is ignited.

If you don't understand what I mean about being messy, talk to any cook who has ever burned a lot of sugar by accident in candy making. Cleaning up the pan while smelling the burnt carmelization isn't pleasant.

There is a reason why military style smoke grenades have a metal casing so the mess is self contained.

thanks for your input

i know most of what you are talking about, and i suppose this science fair topic is going to be scratched .

i also need to know this. i have already created my smoke bomb and lit it up but i am unsure of what is in the smoke created. is it just CO2?

not that it matters now, due date is over and im pretty sure i failed. thanks a lot guys.

Fallen,
Sorry we didn't get to your question in time.
For anyone else who comes along with a similar question, the short answer is, no, smoke is not just composed of CO2. It is a complex mixture of combustion products including aerosols (tiny particles) and gases. An internet search for "smoke composition" will lead you to many pages that provide additional detail. For example:
http://en.wikipedia.org/wiki/Smoke
http://www.newton.dep.anl.gov/askasci/c ... m00927.htm

The reason smoke is "messy" is it usually contains particles of whatever was burning, or it can contain gasses that stain or otherwise damage cloth or paint.

In a small fire, smoke and water damage can cost more to repair than the fire damage. Depending on what you burn, the fumes can not only be messy, but toxic.

Don't experiment with pyrotechnics (fireworks, smoke bombs, similar) without adult supervision from somebody who knows what they are doing. The consequences can lead to all of serious property damage, injury (including blowing off fingers), burns and inhaling toxic substances, which can lead to serious longterm damage or even death.

Most commercial fireworks are fairly safe except for the explosive and fire aspects (you risk burns or an eye or a finger, or setting property on fire). But a homebrew one has a lot of additional risks.