A candle and a firework both can be ignited with a spark, but they release different amounts of energy as they burn. Compare and contrast the potential energy diagrams that would represent each of these burning processes. Be specific in your comparison.

Question

superhelp101 · Answer

@aaronq ?

aaronq · Answer

Well you know that it's going to be an exothermic/exergonic process, so the substance is going to decrease in potential energy. One will be a "burst" of energy given off really fast, the other will take longer, so their slopes will differ.

superhelp101 · Answer

okay. this is what i said does it sound okay...
The candle and firework both are both chemical reactants. So, the conversion of the both candle and firework both substances is ash. Both the candle and firework both release heat. The reaction of the candle and the firework is exothermic. Exothermic means that the reactants have a higher potential energy than the products. Candles and fireworks do not burn spontaneously. This means that unless there is some energy in the form of a spark the reactants will not be able to go. The candle and firework should show an energy barrier diagram. When inflamed or ignited fireworks release much more heat. Therefore, if you were drawing both energy levels from the candle and firework in same diagram, the fireworks would start with more potential energy than the candle. Both the candle and the firework go to the same product, which is ash, therefore both curves end up at the same energy.

aaronq · Answer

it's not bad. Though the products of the reactions are not the same. Candles are made of wax (mostly hydrocarbon chains) while fireworks are for the most part inorganic (metal salts). But they do end up at their lowest potential though.

The firework doesnt necessarily have more PE than the candle. The candle could be very large and hold a lot of wax (which is PE), and the firework could be very small. But it takes less energy to start the combustion reaction of a firework, so the activation energy "hill" should be smaller than the candle's.

superhelp101 · Answer

thank you very much!

aaronq · Answer

no problem!