Which one is most reaction towards `AgNO_3`

Options

A.
B.
C.
D.

Answer

To determine which compound is most reactive towards silver nitrate (AgNO₃), we need to analyze the stability of the carbocations formed during the reaction. The compound that forms the most stable carbocation will be the most reactive.

### Step-by-Step Solution:

1. **Understanding the Reaction**:
When a compound (let's call it R-X) reacts with AgNO₃, it forms a precipitate of AgX and releases a nitrate ion (NO₃⁻). The key to understanding the reactivity lies in the stability of the carbocation (R⁺) that forms when X leaves.

2. **Identifying the Compounds**:
Let's consider the four options provided (though not explicitly listed here, we will assume they are typical organic compounds with different leaving groups):
- Option 1: R-NH₂ (amine)
- Option 2: R-Br (alkyl bromide)
- Option 3: R-OH (alcohol)
- Option 4: R-Ph (aryl compound)

3. **Formation of Carbocations**:
- For each of these compounds, when the leaving group (X) departs, a carbocation is formed. The stability of this carbocation is crucial for determining the reactivity.
- **Option 1**: The lone pair on nitrogen can stabilize the positive charge through resonance.
- **Option 2**: The bromide ion (Br⁻) leaves, forming a carbocation that can be stabilized by hyperconjugation and inductive effects.
- **Option 3**: The hydroxyl group (OH) leaves, forming a carbocation that is less stable due to the lack of effective resonance stabilization.
- **Option 4**: The aryl compound may form a carbocation that is stabilized by resonance, but the presence of the phenyl group can also create steric hindrance.

4. **Comparing Stability**:
- The stability of carbocations generally follows this order: tertiary > secondary > primary > methyl.
- The presence of electron-donating groups (like nitrogen in amines) can stabilize carbocations through resonance.
- In this case, the nitrogen in option 1 can donate its lone pair effectively, making the carbocation more stable compared to the others.

5. **Conclusion**:
Based on the analysis, the compound that forms the most stable carbocation when reacting with AgNO₃ is the one with nitrogen (option 1). Therefore, the most reactive compound towards AgNO₃ is the one that forms the most stable carbocation.

### Final Answer:
The compound that is most reactive towards AgNO₃ is **Option 1** (R-NH₂).