The incorrect reaction is:

Options

A. 1-butene + HCI `to` 2-Chlorobutane
B. Propylene + HCl `to` 2 Chlorobutane
C. 1-butene + HBr `to` 1-Bromobatane
D. 1-butene + HBr `to` 1-Bromobutane

Explanation

To determine the incorrect reaction from the given options, let's analyze each reaction step by step.

### Step 1: Analyze Option 1
**Reaction:** 1-butene + HCl → 2-chlorobutane

1. **Identify the reactants:**
- 1-butene (C4H8) has the structure CH2=CH-CH2-CH3.
- HCl is a strong acid.

2. **Mechanism:**
- The double bond in 1-butene will react with HCl.
- The H+ from HCl will add to the less substituted carbon of the double bond (Markovnikov's rule).
- This forms a carbocation at the more substituted carbon.

3. **Product Formation:**
- The Cl- ion will then attack the carbocation to form 2-chlorobutane (CH3-CHCl-CH2-CH3).

**Conclusion for Option 1:** This reaction is correct.

### Step 2: Analyze Option 2
**Reaction:** Propylene + HCl → 2-chlorobutane

1. **Identify the reactants:**
- Propylene (C3H6) has the structure CH3-CH=CH2.
- HCl is a strong acid.

2. **Mechanism:**
- The double bond in propylene will react with HCl.
- The H+ from HCl will add to the less substituted carbon (the terminal carbon).
- This forms a carbocation at the second carbon.

3. **Product Formation:**
- The Cl- ion will then attack the carbocation to form 2-chloropropane (CH3-CHCl-CH3), not 2-chlorobutane.

**Conclusion for Option 2:** This reaction is incorrect as it produces 2-chloropropane, not 2-chlorobutane.

### Step 3: Analyze Option 3
**Reaction:** 1-butene + HBr → 1-bromobutane (following anti-Markovnikov rule)

1. **Identify the reactants:**
- 1-butene (C4H8) has the structure CH2=CH-CH2-CH3.
- HBr is a strong acid.

2. **Mechanism:**
- When HBr is added in the presence of peroxides, it follows the anti-Markovnikov rule.
- The H+ will add to the less substituted carbon (the terminal carbon).

3. **Product Formation:**
- The Br- ion will then attack the less substituted carbon, leading to the formation of 1-bromobutane (CH3-CH2-CH2-CH2-Br).

**Conclusion for Option 3:** This reaction is correct.

### Final Conclusion
The incorrect reaction is **Option 2**, which states that propylene reacts with HCl to produce 2-chlorobutane. Instead, it produces 2-chloropropane.

---