Question

Is the explosion of fireworks a physical or chemical change?

Answer 1

This is clearly an example of chemical change...........

Explanation:

Chemical change involves the formation of new substances, and the making and breaking of strong chemical bonds. Clearly, the explosion of gunpowder in air fulfills these criteria.

Now everybody knows that gunpowder is a mixture of charcoal, saltpetre, and sulfur. I can write a simple reaction that represents the reaction of gunpowder as:

`8C(s) +10KNO_3(s) +3S(s)rarr6CO_2(g) + 5N_2(g) + 2K_2CO_3(s) +3K_2SO_4(s)`

Is this balanced? Do not trust my arithmetic. Clearly, strong chemical bonds have been broken, and stronger chemical bonds have been formed, most notably `C=O` and `N-=N` bonds, which provide a thermodynamic driving force for the reaction.

Can you imagine the risks involved in this research, and, more so, in the manufacture of gunpowder for munitions? The accidents that have occurred (and these accidents are inevitable) had appalling results.