Silver tarnishes due to the formation of __________

Options

A. oxide layer.
B. sulphide layer.
C. nitride layer.
D. hydride layer.

Answer

**Step-by-Step Solution:**

1. **Understanding Tarnishing**: Tarnishing refers to the process where silver loses its shine and develops a black color. This occurs due to a chemical reaction.

2. **Identifying the Reactants**: Silver (Ag) is not highly reactive, but it can tarnish when it reacts with certain compounds in the atmosphere. The primary compound responsible for tarnishing is hydrogen sulfide (H₂S), which is present in the air.

3. **Chemical Reaction**: The tarnishing of silver can be represented by the following chemical reaction:
\[ 4 \text{Ag} + \text{H}_2\text{S} + \text{O}_2 \rightarrow 2 \text{Ag}_2\text{S} + 2 \text{H}_2\text{O} \]
In this reaction, silver reacts with hydrogen sulfide and oxygen to form silver sulfide (Ag₂S) and water (H₂O).

4. **Formation of Silver Sulfide**: The product of this reaction, silver sulfide (Ag₂S), is a black compound. This is what causes the silver to appear tarnished.

5. **Conclusion**: The tarnishing of silver is due to the formation of a sulfide layer, specifically silver sulfide (Ag₂S). Therefore, the correct answer to the question is that silver tarnishes due to the formation of a **sulfide layer**.

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