A pyrotechnician mixes 280 g of black powder for a firework. Find the amount of oxygen, carbon dioxide, and sulfur dioxide generated when this firework bursts, if the oxidizing agent in the powder is saltpeter. How do I find their amounts?
2 answers
formula for black powder?
The combustion equation for black powder is complex; a simplified balanced equation is as follows:
2 KNO3 + S + 3 C → K2S + N2 + 3 CO2
You can find other equations here:
https://en.wikipedia.org/wiki/Gunpowder#Chemical_reaction
mols saltpeter (KNO3) = g/molar mass = ?
Using the coefficients in the balanced equation, convert mols KNO3 to mols CO2.
Then convert mols CO2 to grams; i.e., grams CO2 = mols CO2 x molar mass CO2 = ?
Do the same for SO2.
It isn't possible to determine O2 formed since this particular equation does not generate O2. You will need to find an equation that generates O2 to do that. My frank opinion, although I'm not an arms expert, is that no excess O2 is generated; i.e., I suspect ALL O2 is used to form CO2, SO2, NO or NO2, etc.
2 KNO3 + S + 3 C → K2S + N2 + 3 CO2
You can find other equations here:
https://en.wikipedia.org/wiki/Gunpowder#Chemical_reaction
mols saltpeter (KNO3) = g/molar mass = ?
Using the coefficients in the balanced equation, convert mols KNO3 to mols CO2.
Then convert mols CO2 to grams; i.e., grams CO2 = mols CO2 x molar mass CO2 = ?
Do the same for SO2.
It isn't possible to determine O2 formed since this particular equation does not generate O2. You will need to find an equation that generates O2 to do that. My frank opinion, although I'm not an arms expert, is that no excess O2 is generated; i.e., I suspect ALL O2 is used to form CO2, SO2, NO or NO2, etc.
7 answers