## **Core Concept**
Black powder, also known as gunpowder, is a mixture of saltpetre (potassium nitrate), charcoal, and sulphur. The combination of these components allows black powder to act as a propellant in firearms and fireworks. The specific composition is crucial for its effectiveness.

## **Why the Correct Answer is Right**
The correct composition of black powder is approximately 75% saltpetre (potassium nitrate), 15% charcoal, and 10% sulphur. This combination works because saltpetre acts as an oxidizer, charcoal serves as the fuel, and sulphur lowers the ignition temperature and increases the burning rate. This synergy enables black powder to burn rapidly, producing a significant amount of gas quickly, which in turn generates high pressure.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not accurately represent the typical composition of black powder.
- **Option B:** This option is incorrect as it also does not match the well-established composition of black powder.
- **Option D:** This option is incorrect because it inaccurately represents the proportions of the components in black powder.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that black powder is highly sensitive to moisture and ignition sources, which is why it is often replaced by more stable and less sensitive propellants in modern applications. However, its historical and current use in certain pyrotechnic and historical reenactments requires careful handling.

## **Correct Answer:** C. 75% saltpetre, 15% charcoal, 10% sulphur.