Consider the following sequence of reaction
The final product (Q) is`Ph-NO_2overset(Sn//HCl)rarr(X)overset(NaNO_2//HCl)rarrPoverset(CuBr//HBr)rarr(Q)` The final product (Q) is

Options

A. chlorbenzene
B. bromobenzene
C. benzyl bromide
D. benzyl chloride

Answer

To solve the given sequence of reactions, we will break down each step and identify the final product (Q).

### Step-by-Step Solution:

1. **Starting Material**: The reaction begins with nitrophenol (Ph-NO2).
- **Reaction**: Ph-NO2 + Sn/HCl → Ph-NH2 (Aniline)
- **Explanation**: The nitro group (NO2) is reduced to an amino group (NH2) using tin (Sn) in hydrochloric acid (HCl). This converts nitrophenol to aniline.

2. **Formation of Diazonium Salt**: The next step involves the conversion of aniline to a diazonium salt.
- **Reaction**: Ph-NH2 + NaNO2/HCl → Ph-N2+Cl- (Diazonium salt)
- **Explanation**: Aniline reacts with sodium nitrite (NaNO2) in the presence of hydrochloric acid (HCl) to form a diazonium salt (Ph-N2+Cl-), which is compound P.

3. **Sandmeyer Reaction**: The diazonium salt undergoes a Sandmeyer reaction to form bromobenzene.
- **Reaction**: Ph-N2+Cl- + CuBr/HBr → Ph-Br (Bromobenzene)
- **Explanation**: The diazonium salt reacts with copper(I) bromide (CuBr) in the presence of hydrobromic acid (HBr) to replace the diazonium group with a bromine atom, yielding bromobenzene as the final product (Q).

### Final Product:
The final product (Q) is **Bromobenzene (Ph-Br)**.

### Summary of Steps:
- Step 1: Reduction of nitrophenol to aniline.
- Step 2: Diazotization of aniline to form diazonium salt.
- Step 3: Sandmeyer reaction to form bromobenzene.