Which is an explosive?

Options

A. Toluene
B. RDX
C. p-nitrophenol
D. All of these

Explanation

To determine which of the substances listed is an explosive, we will analyze each option based on their chemical properties and characteristics.

### Step-by-step Solution:

1. **Understanding Explosives**:
- Explosives are substances that can undergo rapid decomposition, releasing a large amount of gas and heat, which leads to an explosion. They are typically unstable compounds.

2. **Analyzing Toluene**:
- Toluene is an aromatic hydrocarbon with the formula C7H8. While it is flammable and can be dangerous when inhaled, it is not classified as an explosive. Its primary uses are as a solvent in paint thinners and other industrial applications.

3. **Analyzing RDX**:
- RDX stands for Royal Demolition Explosive. Its chemical structure indicates that it is a highly stable compound under normal conditions but can decompose rapidly when initiated (e.g., by heat or shock). RDX is indeed an explosive due to its high nitrogen content and the ratio of carbon to oxygen, which contributes to its instability and explosive properties.

4. **Analyzing p-Nitrophenol**:
- p-Nitrophenol is an organic compound used primarily as a pH indicator. While it can be harmful and has toxic properties, it does not possess the characteristics of an explosive. It can cause irritation and other health issues but does not explode.

5. **Conclusion**:
- Among the three substances analyzed, RDX is the only compound that qualifies as an explosive. Therefore, the correct answer is RDX.

### Final Answer:
**RDX is an explosive.**