Final answer:
Substance P is a component of gunpowder and Substance Q is Potassium nitrate, which provides oxygen for the gunpowder's explosive reaction. Traditional gunpowder includes charcoal, sulfur, and potassium nitrate.
Step-by-step explanation:
Substance P, obtained by destructive distillation of wood, is a component of gunpowder. The substances that make up traditional gunpowder are charcoal, sulfur, and potassium nitrate. Thus, when considering the description of Substance P, it is clear that of the choices given, Substance Q must be d) Potassium nitrate. Potassium nitrate provides the additional oxygen needed for the explosive reaction of gunpowder. When gunpowder ignites, the charcoal converts to carbon dioxide, and the reaction is facilitated by the oxygen from the potassium nitrate. Sulfur's role in gunpowder is to stabilize the mixture and make it more consistent and potent.
Historically, gunpowder was first developed by the Chinese in the 9th century and has been used as an explosive in various applications such as rockets and firearms. It consists of a mixture of the three aforementioned substances which react energetically when ignited, producing gases and heat that can propel projectiles or cause explosions.