A) Addition of HBr on 2-butene gives two isomeric products.
R) Addition of HBr on 2-butene follows Markownikoff's rule.

Options

A. if both Assertion and Reason are true and reason is the correct explanation of the assertion.
B. if both assertion and reason are true but reason is not the correct expalanation of the assertion
C. if assertion is true, reason is false
D. both assertion and reason are false statements.

Explanation

To solve the question, we need to analyze both the assertion (A) and the reason (R) provided:

### Step 1: Understand the structure of 2-butene
2-butene has the molecular formula C4H8 and its structure can be represented as:
\[ \text{CH}_3-\text{CH}=\text{CH}-\text{CH}_3 \]

### Step 2: Addition of HBr to 2-butene
When HBr is added to 2-butene, the double bond between the carbon atoms breaks, and HBr adds across this double bond. The addition involves the electrophilic attack of H+ from HBr and the nucleophilic attack of Br-.

### Step 3: Identify possible products
Due to the symmetrical nature of 2-butene, the addition of HBr can lead to the formation of:
1. 2-bromobutane (where Br attaches to either carbon 2 or carbon 3).
2. However, since both carbons are equivalent in 2-butene, we only get one unique product.

### Step 4: Evaluate the assertion (A)
The assertion states that the addition of HBr on 2-butene gives two isomeric products. This is incorrect because, due to the symmetry of 2-butene, only one product (2-bromobutane) is formed.

### Step 5: Evaluate the reason (R)
The reason states that the addition of HBr on 2-butene follows Markownikoff's rule. Markownikoff's rule states that in the addition of HX to an alkene, the hydrogen atom (H) will attach to the carbon with the greater number of hydrogen atoms already attached. However, since 2-butene is symmetrical, this rule does not apply in a way that leads to different products. Therefore, this statement is also incorrect.

### Conclusion
Both the assertion and the reason are false. Thus, the correct answer is that both statements are incorrect.

### Final Answer:
Both the assertion (A) and the reason (R) are false.

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