Gunpowder is made up of the combination of Potassium Nitrate, sulfer, and charcoal.
- 75% sodium nitrate, 15% charcoal powder and 10% sulfur is the purest combination.
Potassium Nitrate
- Potassium Nitrate comes in wood ash that is purified by recrystalization. In order to extract it you use a metathesis reaction:
Ca(NO3)2(aq) + K2CO3(aq) -----> CaCO3(s) + 2 KNO3(aq)
Sulfur
- Sulfur is one of only a few elements found free in nature (as the element rather than as compounds of that element).
- It is a yellow solid with a melting point of about 120 C.
- It is drilled like oil.
Charcoal
- Charcoal is produced from wood by heating it in a reducing atmosphere (one low in oxygen).
Lift
- The amount of powder needed is equal to the amount required to generate enough force to lift the payload.
- The specific impulse of gunpowder is 500 Ns/kg. So, if you use 2 kg of powder you can get 1000 Ns of impulse. That is 100 m/s for a 10 kg load and this should be able to lift the rocket up to 300 meters.
- My current rocket has 2.5 Kg of powder so it should be able to reach altitudes of about 375 meters.