Styrene when treated with HBr produces :

Options

A.
B.
C.
D.

Explanation

To solve the question of what product is formed when styrene is treated with HBr, we can follow these steps:

### Step 1: Understand the Structure of Styrene
Styrene is an aromatic compound with the formula C8H8. It consists of a benzene ring (C6H5) attached to a vinyl group (C2H3), which can be represented as follows:
- Structure: C6H5-CH=CH2

### Step 2: Identify the Reaction Type
When styrene reacts with HBr, it undergoes an electrophilic addition reaction. In this reaction, the double bond in the vinyl group acts as a nucleophile and attacks the electrophile, which is the hydrogen ion (H+) from HBr.

### Step 3: Electrophilic Attack
In the presence of HBr:
- The double bond (C=C) donates its electrons to H+, resulting in the formation of a carbocation.
- The bromine (Br) atom becomes negatively charged (Br-).

### Step 4: Formation of Carbocation
According to Markovnikov's rule, when HBr adds to an alkene, the hydrogen atom will attach to the carbon with more hydrogen atoms (the less substituted carbon), and the bromine will attach to the carbon with fewer hydrogen atoms (the more substituted carbon). In styrene:
- The carbocation will form at the carbon that is attached to the benzene ring (the more stable position).

### Step 5: Attack of Bromide Ion
After the formation of the carbocation, the bromide ion (Br-) will attack the positively charged carbon, leading to the final product.

### Step 6: Write the Final Product
The final product formed from this reaction is:
- 1-bromo-1-phenylethane (C6H5-CHBr-CH3)

### Conclusion
Thus, when styrene is treated with HBr, it produces 1-bromo-1-phenylethane.