UPSC Prelims 2007 Q122: Science & Technology – Chemistry
Which one of the following does not contain silver?
- (a) Horn Silver
- (b) German Silver
- (c) Ruby Silver
- (d) Lunar Caustic
Answer: (b) German Silver
Explanation
German silver has no silver
| Name | Composition | Contains silver? |
|---|---|---|
| German silver (nickel silver) | Copper + Nickel + Zinc | NO |
| Horn silver | Silver chloride (AgCl) — an ore | Yes |
| Ruby silver | Silver sulphide minerals (pyrargyrite Ag₃SbS₃, proustite Ag₃AsS₃) | Yes |
| Lunar caustic | Silver nitrate (AgNO₃) | Yes |
German silver gets its name from its silvery colour.
It is used in cutlery, keys, musical instruments and coins.
Answer: (b) German Silver.
Why each option is right or wrong
- (a) Incorrect. Horn silver is AgCl — it contains silver.
- (b) CORRECT. German silver is a Cu-Ni-Zn alloy with no silver.
- (c) Incorrect. Ruby silver ores contain silver.
- (d) Incorrect. Lunar caustic is silver nitrate — used in indelible election ink.
Key point
German silver = Cu + Ni + Zn, no silver. Horn silver = AgCl; Lunar caustic = AgNO₃.
Remember
German silver contains copper, nickel and zinc — but no silver.
Common mistakes
- Trusting the name — German silver is named for its look, not its content.
- Not knowing lunar caustic is silver nitrate (used in election ink).
- Confusing horn silver (AgCl) with argentite (Ag₂S).
Exam tip
Misleading names list: German silver (no silver), Lead pencil (no lead — graphite), Soda water (no soda).
Sources
- NCERT Class X — Science, Ch 3 (Metals and Non-metals — alloys)
- NCERT Class XII — Chemistry, Ch 6 (General Principles of Isolation of Elements)