Sorry, Last Instant Fire Question

[HelloHelp100]

Last Question, this is my consensus, please help:

 

After doing extensive research, where we mixed potassium chlorate and sugar and then added sulfuric acid to produce a purple fire. So far we used the equation 2KClO3(s) —heat—> 2KCl(s) + 3O2(g) and said the sugar was a catalyst in the sense that it was used as a fuel to accelerate the combustion reaction. Also, we said that other fuels could replace sugar and the reaction would be the same, and sugar is just easy to use, so it does not need to be mentioned in the equation; and sulfuric acid was just a spectator. Therefore, this equation shows only the decomposition of potassium chlorate. Some sources agreed with this, but others disagreed. Other sources have used C12H22O11(s) + 8KClO3(s) --heat--> 12CO2(g) + 11H2O(g) + 8KCl(s) + 2029 kJ as the actual reaction, and said sugar was not a catalyst but a necessary reactant. Are we correct? Is sugar a catalyst?

[woelen]

No, you are not correct. Sugar is the fuel, which is burnt. The reaction indeed can be described as

 

C12H22O11(s) + 8KClO3(s) --heat--> 12CO2(g) + 11H2O(g) + 8KCl(s)

 

Of course, it is idealized, in reality you also will have some incompletely burnt sugar. But definitely, the sugar is used up and it is no catalyst.

 

The H2SO4 also is not a spectator, it is used to light the mix. In order to get the reaction going, it must be ignited. That can be done with heat, e.g. lighting with a match. You can also use H2SO4. H2SO4 reacts with KClO3, one of the reaction products being ClO2. This compound is VERY reactive and reacts with the sugar, even at room temperature, giving enough heat to initiate further combustion.

[jdurg]

The classic version of this reaction is taking a pyrex test-tube and putting some anhydrous KClO3 in there. Place this over a bunsen burner until the salt becomes liquid. Then you drop some sugar in there (usually in the form of a gummy bear) and it immediately ignites and burns as the liberated oxygen combusts the sugars.