Assertion: in comparison to ethyl chloride it is difficult to carry out nucleophilic on vinyl chloride
Reason: Vinyl group is electron-donating .

Options

A. a. If both Assertion and Reason are true and Reason is correct explanation of Assertion.
B. b. If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
C. c. If Assertion is true but Reason is false.
D. d. If both Assertion and Reason and false.

Answer

To solve the question, we need to analyze the assertion and the reason provided.

### Step 1: Understand the Structures
- **Ethyl Chloride (C2H5Cl)**: This compound has a simple alkyl structure with a chlorine atom attached to a carbon atom. The carbon atom is sp3 hybridized, which means it forms single bonds and has a tetrahedral geometry.

- **Vinyl Chloride (CH2=CHCl)**: This compound has a double bond between two carbon atoms. The carbon atom bonded to chlorine is sp2 hybridized, which means it has a trigonal planar geometry.

**Hint**: Draw the structures of both ethyl chloride and vinyl chloride to visualize the differences in bonding.

### Step 2: Analyze Nucleophilic Attack
- In ethyl chloride, the carbon atom bonded to chlorine is less hindered and has a partial positive charge due to the electronegativity of chlorine. This makes it more susceptible to nucleophilic attack.

- In vinyl chloride, the presence of the double bond gives the carbon atom bonded to chlorine a partial double bond character. This means that the bond between the carbon and chlorine is stronger and less reactive towards nucleophiles.

**Hint**: Consider how the hybridization of the carbon atom affects the reactivity towards nucleophiles.

### Step 3: Evaluate the Assertion
- The assertion states that it is difficult to carry out nucleophilic substitution on vinyl chloride compared to ethyl chloride. This is true because the double bond and the partial double bond character make the carbon less reactive.

**Hint**: Reflect on why the presence of a double bond would affect the reactivity of a molecule.

### Step 4: Evaluate the Reason
- The reason provided states that the vinyl group is electron-donating. This is incorrect. The vinyl group does not donate electrons; instead, it has a partial positive charge due to the double bond, which makes it less reactive towards nucleophiles.

**Hint**: Think about the nature of electron-donating and electron-withdrawing groups in organic chemistry.

### Conclusion
- The assertion is true, but the reason is false. Therefore, the correct answer is that the assertion is true, but the reason is false.

### Final Answer
- The correct option is C: "If assertion is true, but the reason is false."