The mechanism of SN1 reaction is given below :
`CH_(3)-underset(CH_(3)) underset(|) overset(CH_(3)) overset(|)C-Broverset("step-1")toCH_(3)-underset(CH_(3)) underset(|)overset(o+)C-CH_(3)+ overset(o+)(Br) overset(Nu)underset("step-II")to CH_(3)- underset(CH_(3)) underset(|)overset(CH_(3))overset(|)C-Nu`
Given answer of the following questions on the basis of the machanism given below.
Which statement is NOT correct ?

Options

A. The reaction is first order reaction with respect to `overset(o+)Nu`
B. The reaction is first order with respect to alkyl halide
C. tert-butyl iodides is more reactive that tert-buty chloride
D. Opticlly active alkyl halide gives enatiomers

Answer

To determine which statement is NOT correct based on the given mechanism of the SN1 reaction, we can analyze the statements one by one.

### Step-by-Step Solution:

1. **Understanding the SN1 Mechanism**:
- The SN1 reaction mechanism involves two main steps:
- **Step 1**: The formation of a carbocation after the leaving group departs.
- **Step 2**: The nucleophile attacks the carbocation to form the final product.

2. **Analyzing the Statements**:
- **Statement 1**: "The reaction is first order with respect to the nucleophile."
- This statement is incorrect. In an SN1 reaction, the rate of reaction depends only on the concentration of the alkyl halide and not on the nucleophile. Therefore, this statement is NOT correct.

- **Statement 2**: "Tertiary Butyl Iodide is more reactive than Tertiary Butyl Chloride."
- This statement is correct. Iodide (I-) is a better leaving group than chloride (Cl-) due to its larger size and better stability as a negative ion. Thus, tertiary butyl iodide will react faster than tertiary butyl chloride.

- **Statement 3**: "Optically active alkyl halides give enantiomers."
- This statement is also correct. When an optically active alkyl halide undergoes an SN1 reaction, the nucleophile can attack from either side of the planar carbocation, leading to the formation of both enantiomers.

3. **Conclusion**:
- The statement that is NOT correct is the first one: "The reaction is first order with respect to the nucleophile."

### Final Answer:
The statement that is NOT correct is: "The reaction is first order with respect to the nucleophile."

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