Silverware turns black after a period of time due to formation of

Options

A. nitrate coating on silver
B. sulphide coating on silver
C. chloride coating on silver
D. oxide coating on silver

Explanation

**Step-by-Step Solution:**

1. **Understanding the Problem**: The question asks why silverware turns black over time. This phenomenon is commonly observed and is due to a chemical reaction.

2. **Identifying the Cause**: Silverware tarnishes when it comes into contact with certain substances in the environment. One of the most common culprits is hydrogen sulfide (H₂S), which can be found in the air, especially in polluted areas or in the presence of certain foods.

3. **Chemical Reaction**: When silver (Ag) reacts with hydrogen sulfide (H₂S), it forms silver sulfide (Ag₂S). This compound is black in color, which is why the silverware appears to turn black.

The chemical equation for this reaction can be represented as:
\[ 2 \, \text{Ag} + \text{H}_2\text{S} \rightarrow \text{Ag}_2\text{S} + \text{H}_2 \]

4. **Conclusion**: Therefore, the black coating observed on silverware is due to the formation of silver sulfide (Ag₂S) as a result of the reaction between silver and hydrogen sulfide in the air.

5. **Final Answer**: Silverware turns black after a period of time due to the formation of silver sulfide (Ag₂S).

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