Which of the following statements is incorrect for ethylene dichloride and ethylidene chloride?

Options

A. These are structural isomers
B. Both of these yields same product on reaction with alcoholic KOH solution
C. Both of these yeilds same product on treatement with aqueous KOH solution
D. Both of these yeilds same product on reduction

Answer

To solve the question regarding ethylene dichloride and ethylidene chloride, we will analyze the provided statements one by one to determine which one is incorrect.

### Step 1: Identify the Structures
1. **Ethylene Dichloride (1,2-Dichloroethane)**:
- Structure:
\[ \text{CH}_2\text{Cl}-\text{CH}_2\text{Cl} \]
- This compound has two carbon atoms, four hydrogen atoms, and two chlorine atoms (C2H4Cl2).

2. **Ethylidene Chloride (1-Chloro-1-ethene)**:
- Structure:
\[ \text{CH}_3-\text{C}(\text{Cl})=\text{CH}(\text{Cl}) \]
- This compound also has two carbon atoms, four hydrogen atoms, and two chlorine atoms (C2H4Cl2).

### Step 2: Analyze the Statements
1. **Statement 1**: "These are structural isomers."
- **Analysis**: Both compounds have the same molecular formula (C2H4Cl2) but different structures. This statement is **correct**.

2. **Statement 2**: "Both of these yield the same product on reaction with alcoholic KOH."
- **Analysis**:
- Ethylene dichloride undergoes elimination to form an alkene (ethene).
- Ethylidene chloride also undergoes elimination to form the same alkene (ethene).
- This statement is **correct**.

3. **Statement 3**: "Both of these yield the same product on treatment with aqueous KOH."
- **Analysis**:
- Ethylene dichloride reacts with aqueous KOH to undergo substitution, resulting in the formation of 1,2-ethanediol (glycol).
- Ethylidene chloride reacts with aqueous KOH to also undergo substitution, but it leads to the formation of a different product, specifically 1-chloro-2-ethanol and then dehydration to form acetaldehyde.
- This statement is **incorrect**.

4. **Statement 4**: "Both of these yield the same product on reduction."
- **Analysis**: Both compounds, when reduced, yield ethane (C2H6).
- This statement is **correct**.

### Conclusion
The incorrect statement among the options provided is:
- **"Both of these yield the same product on treatment with aqueous KOH."**