Addition of `Br_2` to trans-2-butene would give a product which is

Options

A. achiral
B. racemic
C. meso
D. optically active

Explanation

To solve the question regarding the addition of \( Br_2 \) to trans-2-butene, we will follow these steps:

### Step 1: Draw the structure of trans-2-butene
Trans-2-butene has the following structure:

\[ \text{CH}_3-CH=CH-CH_3 \]

In this structure, the two methyl groups (\( CH_3 \)) are on opposite sides of the double bond, which is characteristic of the trans isomer.

### Step 2: Understand the addition reaction
When bromine (\( Br_2 \)) is added to alkenes, it typically undergoes an electrophilic addition reaction. In the case of trans-2-butene, the addition of bromine occurs via an anti-addition mechanism. This means that the bromine atoms will add to opposite sides of the double bond.

### Step 3: Draw the bromonium ion intermediate
During the reaction, a bromonium ion is formed as an intermediate. This ion is a cyclic structure where one bromine atom is bonded to one of the carbons in the double bond, creating a positive charge on the other carbon.

### Step 4: Complete the addition of bromine
The second bromine atom will then attack the bromonium ion from the opposite side (anti-addition), leading to the formation of a dibromide product. The product formed from trans-2-butene will have the following structure:

\[ \text{CH}_3-CHBr-CHBr-CH_3 \]

### Step 5: Analyze the symmetry of the product
The final product is a meso compound because it has a plane of symmetry. The two bromine atoms are added to the same side of the molecule, but since the original alkene was trans, the resulting compound will have a mirror plane dividing the molecule into two symmetrical halves.

### Step 6: Conclusion
The product of the addition of \( Br_2 \) to trans-2-butene is a meso compound.

### Final Answer
The correct answer is that the product is **meso**.

---