First of all there are only 378 combinations (since A+B is the same as B+A), so it is a lot more manageable. I am not asking someone to solve every one of these combinations, because that is overkill. I am looking for people that recognize two chemicals as ones that react interestingly with each other.
I have 3 of the six I want to do already: Hydrogen peroxide + iron (II) sulfate which reduces the peroxide (formation of gases), Sodium Chloride + Silver nitrate to form silver chloride (precipitate formed), and Iron (III) chloride + potassium thiocyanate to make the theatrical "blood" (color change).
The five common signs of a chemical reaction are: production of gases, change in color, change in odor, precipitate formation, and the release of energy (sound, light, heat, etc). To make this lab worthwhile, I would like to have at least one of each. For the odor, a sulfur containing compound would be a good start, correct?
If I decide to go too far on this I will solve each one of the 378 reactions to find out if they react in the first place, and then their products and so on.