UPSC Prelims 2009 Q72: Science & Technology – Chemistry
Which one of the following is used as an explosive ?
- (a) Phosphorus trichloride
- (b) Mercuric oxide
- (c) Graphite
- (d) Nitroglycerine
Answer: (d) Nitroglycerine
Explanation
Which substance is used as an explosive
Among these four chemical compounds, only one is specifically known for its explosive properties.
| Option | Verdict | Reason |
|---|---|---|
| (a) Phosphorus trichloride | Incorrect | Used in chemical synthesis, not as an explosive |
| (b) Mercuric oxide | Incorrect | Used in certain chemical/industrial applications, not primarily as an explosive |
| (c) Graphite | Incorrect | A form of carbon, used as a lubricant/conductor, not an explosive |
| (d) Nitroglycerine | Correct | Nitroglycerine is a well-known explosive compound, historically used in dynamite |
Nitroglycerine facts:
| Point | Detail |
|---|---|
| Use | Explosive (e.g., in dynamite) |
| Property | Highly unstable, releases energy rapidly upon detonation |
Answer: (d) Nitroglycerine.
Why each option is right or wrong
- (a) Incorrect. Phosphorus trichloride is used in chemical synthesis, not as an explosive.
- (b) Incorrect. Mercuric oxide has other industrial uses, not primarily explosive.
- (c) Incorrect. Graphite is a lubricant/conductor, not an explosive.
- (d) CORRECT. Nitroglycerine is a well-known explosive compound.
Key point
Nitroglycerine is used as an explosive — Phosphorus trichloride, Mercuric oxide, and Graphite serve entirely different chemical/industrial purposes.
Remember
Nitroglycerine: used as an explosive.
Common mistakes
- Confusing nitroglycerine's explosive application with other industrial-sounding chemical compounds.
- Not knowing graphite's actual use as a lubricant/conductor rather than an explosive.
- Assuming any unfamiliar chemical name could be an explosive.
Exam tip
Nitroglycerine = explosive (used in dynamite). The other three listed compounds have entirely different industrial uses.
Sources
- Encyclopaedia Britannica — nitroglycerin
- Encyclopaedia Britannica — dynamite