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statement I: Addition of Br(2) to 1-bute...

statement I: Addition of `Br_(2)` to `1`-butene gives two optical isomers.
statement II: The product contains one asymmetric carbon atoms.

A

Statement `I` is true, Statement `II` is true, Statement `II` is the correct explanation of Statement `I`.

B

Statement`I` is true, Statement`II` is true, Statement `II` is not the correct explanation of Statement `I`.

C

Statement `I` is true, Statement `II` is false.

D

Statement `I` is false, Statement `II` is true.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze both statements regarding the addition of \( \text{Br}_2 \) to 1-butene. ### Step 1: Understand the Reaction 1-butene is an alkene with the structure \( \text{CH}_2=\text{CH}-\text{CH}_2-\text{CH}_3 \). When \( \text{Br}_2 \) is added to 1-butene, the double bond reacts with bromine. ### Step 2: Draw the Reaction Mechanism 1. The \( \text{Br}_2 \) molecule approaches the double bond in 1-butene. 2. The pi electrons from the double bond attack one of the bromine atoms, leading to the formation of a cyclic bromonium ion intermediate. 3. The other bromine atom (now a bromide ion, \( \text{Br}^- \)) attacks the more substituted carbon of the bromonium ion. ### Step 3: Identify the Product After the attack of \( \text{Br}^- \), we get a dibromide product: - The product can be represented as \( \text{CH}_3-\text{CH}_2-\text{C}(\text{Br})-\text{CH}_2(\text{Br}) \). ### Step 4: Determine Chirality In the product, the carbon atom that has the bromine attached becomes a chiral center because it is bonded to four different groups: 1. \( \text{Br} \) 2. \( \text{H} \) 3. \( \text{CH}_2\text{Br} \) 4. \( \text{CH}_3\text{CH}_2 \) Since this carbon is attached to four different substituents, it is asymmetric (chiral). ### Step 5: Optical Isomers A molecule with one chiral center can exist in two enantiomeric forms (optical isomers). Therefore, the addition of \( \text{Br}_2 \) to 1-butene will yield two optical isomers. ### Conclusion - **Statement I**: True, because the addition of \( \text{Br}_2 \) to 1-butene results in two optical isomers. - **Statement II**: True, because the product contains one asymmetric carbon atom. Thus, both statements are true, and statement II correctly explains statement I. ### Final Answer Both statements are true, and statement II is the correct explanation of statement I. ---

To solve the question, we need to analyze both statements regarding the addition of \( \text{Br}_2 \) to 1-butene. ### Step 1: Understand the Reaction 1-butene is an alkene with the structure \( \text{CH}_2=\text{CH}-\text{CH}_2-\text{CH}_3 \). When \( \text{Br}_2 \) is added to 1-butene, the double bond reacts with bromine. ### Step 2: Draw the Reaction Mechanism 1. The \( \text{Br}_2 \) molecule approaches the double bond in 1-butene. 2. The pi electrons from the double bond attack one of the bromine atoms, leading to the formation of a cyclic bromonium ion intermediate. ...
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Knowledge Check

  • Addition of Br_2 to cis-2-butene would give a product which is:

    A
    achiral
    B
    racemic
    C
    meso
    D
    optically active
  • Addition of Br_2 to trans-2-butene would give a product which is

    A
    achiral
    B
    racemic
    C
    meso
    D
    optically active
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