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📌 The Question:

What is the common characteristic of the chemical substances generally known as CL-20, HMX and LLM-105, which are sometimes talked about in media?

(a) These are alternatives to hydro-fluorocarbon refrigerants
(b) These are explosives in military weapons
(c) These are high-energy fuels for cruise missiles
(d) These are fuels for rocket propulsion

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✅ Correct Answer: (b) These are explosives in military weapons

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🧠 Classroom Explanation (Straight & Sharp):

CL-20, HMX, and LLM-105 all belong to the category of high-energy military explosives, not fuels or refrigerants.

Let us decode each briefly 👇

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🔹 CL-20 (Hexanitrohexaazaisowurtzitane)

• One of the most powerful non-nuclear explosives known
• Belongs to cage-structured nitramines
• Extremely high detonation velocity and energy density
• Major limitation: very sensitive to shock and friction

👉 Used in advanced warheads and specialized military applications

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🔹 HMX (Octogen)

• A high-melting nitramine explosive
• More powerful than RDX, less than CL-20
• Widely used in:

• Military-grade plastic explosives
• Shaped charges
• High-performance warheads

👉 Known for high detonation pressure and stability

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🔹 LLM-105

• A new-generation “Insensitive High Explosive (IHE)”
• Designed to balance power with safety
• Low sensitivity to heat, friction, and impact

👉 Preferred where handling safety is critical without compromising lethality

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📌 Key Takeaway:
All three are explosives, not fuels.
Fuel ≠ Explosive (a classic UPSC trap).

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🔍 Curiosity Raiser:
💥 Why does the military want insensitive explosives?
→ Because modern warfare demands maximum destructive power with minimum accidental detonation risk during transport and storage.

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📚 Enrich Notes (UPSC Value-Add):

• Explosives vs Fuels

• Explosives: Instantaneous energy release (detonation)
• Fuels: Controlled combustion (propulsion)

• Trend in defence R&D:
From maximum power → power + safety (LLM-105 style)

• Frequently confused terms in prelims:

• Explosives ❌ Rocket fuels
• Detonation ❌ Combustion

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🪶 IAS Monk Whisper:
When UPSC names chemicals with codes and hyphens, suspect defence, not climate or energy.