MrBannerman

Howdy! I'm Matthew, and I teach high school science! It's nice to find these forums! Also, from that first paragraph, it seems like I'm a pretty excited fella. I'm only REALLY excited about transmembrane signals that involve carbohydrate complexes, and anything involving organic chemistry.

Realizing that I am currently necro-posting by raising a two year old post, how does this affect the common conception that you need a '3:2 ratio by weight' of saltpeter to sucrose? This (exceptionally well balanced) equation seems to indicate that you, in fact, need a 24:1 molar ratio of saltpeter to sucrose - if you have 376g of sucrose (which is about 1 cup, according to accepted volume and density conversions), you'd need 2668.03g of saltpeter. That's a 7:1 ratio by weight. If we use the density and conversion factors to convert that mass back to cups, you get around 3.4 cups, which is still a 3.4:1 ratio by volume. To truly have an excess of nitrate, you would have to have an exceptional amount of it. Otherwise, it's always going to be the sugar that's present in excess. EDIT: Talking with a colleague, we decided that the excess sugar in these devices is probably to keep the KNO3 from exploding or just burning off too quickly to produce meaningful smoke. I haven't tried making a device in the appropriate molar ratio yet (that's on the list for next week, after I get more saltpeter), but I will and I will let people know how it goes. =)