Final answer:
The composition of black powder in a firework is potassium nitrate, charcoal, and sulfur. Chemical equations for reactions involving barium nitrate, potassium chlorate, and the combustion of metals like magnesium, aluminum, and iron are provided.
Step-by-step explanation:
The composition of the black powder in a firework is a) Potassium nitrate, charcoal, and sulfur. This mixture is also known as gunpowder and has been historically used as an explosive material. The potassium nitrate provides oxygen for the combustion of charcoal (carbon), while sulfur acts as a stabilizer to improve the performance of the gunpowder.
Answering the other chemistry details in the question:
- (a) The formulas for barium nitrate and potassium chlorate are Ba(NO3)2 and KClO3, respectively.
- (b) The decomposition reaction of potassium chlorate (KClO3) is:
2 KClO3(s) → 2 KCl(s) + 3 O2(g) - (c) The decomposition reaction of barium nitrate (Ba(NO3)2) is:
2 Ba(NO3)2(s) → 2 BaO(s) + 4 NO2(g) + O2(g) - (d) The reactions of magnesium, aluminum, and iron with oxygen to form their oxides are:
Mg(s) + 1/2 O2(g) → MgO(s)4 Al(s) + 3 O2(g) → 2 Al2O3(s)4 Fe(s) + 3 O2(g) → 2 Fe2O3(s)
For the blank in the equation provided in part 8, the single chemical formula for a covalent compound that will balance the equation is H2O (water).