The colour developed when sodium sulphide is added to sodium nitroprusside is

Options

A. Violet
B. yellow
C. Red
D. Black

Explanation

To determine the color developed when sodium sulfide is added to sodium nitroprusside, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The two reactants involved in the reaction are sodium sulfide (Na2S) and sodium nitroprusside (Na2Fe(CN)5NO).

2. **Write the Reaction**:
- When sodium sulfide is added to sodium nitroprusside, a chemical reaction occurs. The equation can be represented as:
\[ \text{Na}_2\text{S} + \text{Na}_2\text{Fe(CN)}_5\text{NO} \rightarrow \text{Na}_4\text{Fe(CN)}_5\text{NO} + \text{other products} \]
- The main product of interest here is the complex formed.

3. **Identify the Product**:
- The product formed from this reaction is a complex compound, specifically Na4Fe(CN)5NO.

4. **Determine the Color of the Product**:
- The complex Na4Fe(CN)5NO is known to exhibit a violet color when formed.

5. **Select the Correct Option**:
- Among the options provided (violet, yellow, red, black), the color of the compound formed is violet.

### Final Answer:
The color developed when sodium sulfide is added to sodium nitroprusside is **violet**.

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