`Cd(CN)_(2)darr+2KCN to K_(2)[Cd(CN)_(4)]`

Options

A. For precipitate formation reaction
B. For precipitate dissolution reaction
C. For precipitate exchange reaction
D. For no reaction

Answer

To analyze the given reaction \( \text{Cd(CN)}_2 + 2 \text{KCN} \rightarrow \text{K}_2[\text{Cd(CN)}_4] \), we need to determine the type of reaction it represents. Here’s a step-by-step breakdown:

### Step 1: Identify the Reactants and Products
The reactants in this reaction are:
- Cadmium cyanide, \( \text{Cd(CN)}_2 \)
- Potassium cyanide, \( \text{KCN} \)

The product is:
- Potassium tetra-cyanocadmate, \( \text{K}_2[\text{Cd(CN)}_4] \)

### Step 2: Analyze the Nature of the Reaction
In this reaction, \( \text{Cd(CN)}_2 \) is a complex that can be considered as a precipitate. The presence of a downward arrow in the reaction indicates that \( \text{Cd(CN)}_2 \) is not soluble in the solution and is thus a solid precipitate.

### Step 3: Determine the Type of Reaction
The reaction involves the dissolution of a precipitate \( \text{Cd(CN)}_2 \) in the presence of \( \text{KCN} \) to form a soluble complex \( \text{K}_2[\text{Cd(CN)}_4] \). Since the precipitate is dissolving to form a soluble product, this reaction can be classified as a **precipitate dissolution reaction**.

### Conclusion
The reaction \( \text{Cd(CN)}_2 + 2 \text{KCN} \rightarrow \text{K}_2[\text{Cd(CN)}_4] \) is a **precipitate dissolution reaction**.

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