Which of the following is the industrial method of preparation of acetaldehyde

Options

A. `CH_3CNoverset(Sncl_2)underset(HCL)rarrCH_3CH=NHoverset(H_2O^+)rarrCH_3CHO`
B. `CH_3COCl+H_2overset(Pd)underset(BaSO_4)rarrCH_3CHO+HCL`
C. `CH_2=CH_2+H_2Ooverset(Pd^(2+))rarrCH_3CHO`
D. All of the above

Answer

To determine the industrial method of preparation of acetaldehyde, we will analyze the options provided and identify the correct method.

### Step-by-Step Solution:

1. **Understanding Acetaldehyde**: Acetaldehyde (CH3CHO) is an important organic compound used in various industrial applications.

2. **Identifying the Industrial Method**: The question asks for the industrial method of preparation of acetaldehyde. The most common industrial method is the oxidation of ethylene (C2H4) through the Wacker process.

3. **Wacker Process**:
- In this process, ethylene is oxidized in the presence of a palladium-copper catalyst.
- The reaction can be summarized as:
\[ \text{C}_2\text{H}_4 + \text{O} \xrightarrow{\text{Palladium-Copper}} \text{CH}_3\text{CHO} \]
- This method is efficient and widely used in the industry for producing acetaldehyde.

4. **Analyzing the Options**:
- **Option A**: Involves CH3CN with SnCl2 and HCl, leading to an intermediate before forming acetaldehyde. This is not an industrial method due to the complexity and multiple steps involved.
- **Option B**: Involves CS3COCl and H2 in the presence of palladium and BaS4 (Rosenmund reduction). This is also not an industrial method for producing acetaldehyde.
- **Option C**: Refers to the oxidation of ethylene using a palladium catalyst, which is the Wacker process and is indeed the industrial method for producing acetaldehyde.

5. **Conclusion**: After analyzing the options, the correct answer is option C, which corresponds to the Wacker process using ethylene.

### Final Answer:
**The industrial method of preparation of acetaldehyde is through the oxidation of ethylene (C2H4) using the Wacker process (Option C).**

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