Equal amount of aqueous solution of `CuSO_4` and alkaline sodium potassium tartarate is mixed and treated with aliphatic aldehyde, then

Options

A. Red brown ppt of `Cu_2O` is formed
B. Red brown ppt of Cuo is formed
C. Blue ppt of CuO is formed
D. There will be no reaction

Answer

To solve the problem, we need to analyze the reaction that occurs when equal amounts of aqueous solutions of CuSO4 (copper(II) sulfate) and alkaline sodium potassium tartrate are mixed and then treated with an aliphatic aldehyde.

### Step-by-Step Solution:

1. **Understanding the Components**:
- CuSO4 is a copper(II) salt that can exist in an aqueous solution.
- Sodium potassium tartrate is the sodium and potassium salt of tartaric acid, which is alkaline in nature.

2. **Formation of the Complex**:
- When CuSO4 is mixed with sodium potassium tartrate in an alkaline solution, a complex is formed. This complex is known as "Fehling's solution" (specifically, Fehling's A and Fehling's B).
- The tartrate ion acts as a complexing agent for the Cu²⁺ ions, stabilizing them in solution.

3. **Reaction with Aliphatic Aldehyde**:
- Aliphatic aldehydes, such as formaldehyde or acetaldehyde, can act as mild reducing agents.
- When an aliphatic aldehyde is added to the Fehling's solution, it reduces the Cu²⁺ ions to Cu⁺ ions.

4. **Observation of the Reaction**:
- The reduction of Cu²⁺ to Cu⁺ results in the formation of a red-brown precipitate of copper(I) oxide (Cu2O).
- This precipitate is typically observed as a result of the reaction, indicating that the aldehyde has been oxidized to a carboxylic acid.

5. **Conclusion**:
- The final observation when mixing the solutions and adding the aliphatic aldehyde is the formation of a red-brown precipitate of Cu2O.

### Final Answer:
When equal amounts of aqueous solutions of CuSO4 and alkaline sodium potassium tartrate are mixed and treated with an aliphatic aldehyde, a red-brown precipitate of Cu2O is formed.

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