[chris]

Hello my name is Chris and I’m a high school student doing science fair on rocket motors. My mentor showed me the process of making rocket candy (a propellant made from corn starch potassium nitrate and sugar). But he also wants me to learn why rocket candy works the way it does. So I thought I should start off by balancing the equation but that sounds a lot simpler than it is.

Long story short I need help balancing this equation C6H12O6+C12H22O11+KNO3=CO2+CO+H2O+H2+N2+K2CO3+KOH
if you could help me with this I would be very thank full

[UG]

C₆H₁₂O₆ + C₁₂H₂₂O₁₁ + KNO₃ CO₂ + CO + H₂O + H₂ + N₂ + K₂CO₃ + KOH

This definitely isn't for the faint hearted. 
What I did first was balance the K, there were 3 K on the left and one on the right, so I put a 2 in front of the KOH and a 4 in front of the KNO₃ and that's sorted. Then I gambled that there would only be one molecule of C₆H₁₂O₆ and C₁₂H₂₂O₁₁. So that left me with balancing the carbon. There were 18 C's. There was already one carbon on K₂CO₃ so that left me with 17 C's to split between CO₂ and CO. There were 29 O's and 5 were used in the potassium compounds so I was left with 24 O's to split between H₂O, CO₂ and CO. Since there was only 17 C's, there must be more CO than CO₂ and this would have to be an odd number since the number of O's added to an even number, 24 (odd + odd = even). I did this and I got 4CO₂ + 13CO + 3H₂O. Then the rest is pretty easy because all you have to do is balance out the N's and the H's. I'm sure you'll manage.
Howszat sound? 
 

[chris]

  wow thank u so much u have no idea how long i have been working on this

[Borek]

There is no ONE solution, there is infinite number of solutions.

See

http://www.chembuddy.com/?left=balancing-stoichiometry&right=balancing-failure

for explanation, and compare with

http://www.chemicalforums.com/index.php?topic=8057.msg38533#msg38533

With two reactions being:

4C₁₂H₂₂O₁₁ + 2KNO₃ -> 48CO + 43H₂ + N₂ + 2KOH
5C₆H₁₂O₆ + 24KNO₃ -> 18CO₂ + 30H₂O + 12N₂ + 12K₂CO₃

(this is only one possible pair, much more can be generated juggling CO₂/CO, H₂O/H₂ and KOH/K₂CO₃).