An excellent lubricant amongst these is

Options

A. Molybdenum disulphide
B. Tungsten carbide
C. Ferrocene
D. Chromium Trioxide

Explanation

To determine the excellent lubricant among the given options, we need to analyze each substance based on its properties and applications.

### Step-by-Step Solution:

1. **Identify the Options**: The options provided are:
- Molybdenum disulphide (MoS2)
- Tungsten carbide (WC)
- Ferrocene (C10H10Fe)
- Chromium trioxide (CrO3)

2. **Analyze Molybdenum Disulphide (MoS2)**:
- Molybdenum disulphide is known for its lubricating properties.
- It is less reactive and can withstand high temperatures.
- It is unaffected by dilute acids, making it a stable lubricant.
- Commonly used in greases and as a solid lubricant in various applications.

3. **Analyze Tungsten Carbide (WC)**:
- Tungsten carbide is primarily used for its hardness and wear resistance.
- It is not typically used as a lubricant but rather in cutting tools and industrial applications.

4. **Analyze Ferrocene (C10H10Fe)**:
- Ferrocene is an organometallic compound.
- It is used mainly in research and medical applications, such as cancer research.
- It does not have significant lubricating properties.

5. **Analyze Chromium Trioxide (CrO3)**:
- Chromium trioxide is used mainly for chromium plating and enhancing corrosion resistance.
- It is not utilized as a lubricant.

6. **Conclusion**: Based on the analysis, Molybdenum disulphide (MoS2) is identified as the excellent lubricant among the options provided.

### Final Answer:
The excellent lubricant among the given options is **Molybdenum disulphide (MoS2)**.

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