Which of the following chemicals are vastly used in gunpowder of fireworks?

Potassium nitrate, sulphur and charcoal

The correct answer is option 4. Potassium nitrate, sulphur and charcoal.

Gunpowder, also known as black powder, is a chemical mixture used in fireworks to produce colorful explosions. The traditional composition of gunpowder consists of three main components:

Potassium Nitrate (KNO₃): Potassium nitrate, also known as saltpeter, is a key ingredient in gunpowder. It provides a source of oxygen for the combustion process. When heated, potassium nitrate releases oxygen, supporting the rapid burning of other components.

Sulfur (S): Sulfur is another essential component of gunpowder. It enhances the burning characteristics of the mixture and contributes to the overall combustion process. Sulfur helps control the rate of burning and produces specific colors in the flame.

Charcoal (Carbon, C):  Charcoal, primarily composed of carbon, serves as the fuel in gunpowder. During the combustion process, charcoal reacts with oxygen released by potassium nitrate, generating carbon dioxide and a significant amount of heat.

The balanced chemical equation for the combustion of gunpowder is complex and involves multiple reactions. However, a simplified representation is as follows:

\[ 2 \text{KNO₃} + \text{S} + 3\text{C} \rightarrow \text{K₂S} + \text{N₂} + 3\text{CO₂} \]

The products of this reaction include potassium sulfide (\( \text{K₂S} \)), nitrogen gas (\( \text{N₂} \)), and carbon dioxide (\( \text{CO₂} \)). The release of gases, heat, and the production of solid particles during combustion result in the explosive and visually appealing effects in fireworks.

In summary, the combination of potassium nitrate, sulfur, and charcoal creates gunpowder, providing the necessary components for combustion and generating the vibrant colors and explosive effects seen in fireworks displays.