Inorganic benzene reacts with HCl to form a compounds `B_(3)N_(3)H_(9)Cl_(3)`. The protonation occurs at:

Options

A. B-atom
B. N-atom
C. First at B-atom than rearranges into N-atom
D. first at N-atom then rearranges into B-atom

Explanation

To solve the problem of where protonation occurs in the reaction of inorganic benzene with HCl to form the compound \( B_3N_3H_9Cl_3 \), we can follow these steps:

### Step 1: Understand the Structure of Inorganic Benzene
Inorganic benzene, also known as borazine, has the formula \( B_3N_3H_6 \). Its structure consists of alternating boron (B) and nitrogen (N) atoms in a cyclic arrangement, similar to benzene. Each boron atom is bonded to one hydrogen atom, while each nitrogen atom is bonded to one hydrogen atom as well.

**Hint:** Familiarize yourself with the structure of borazine to understand the bonding and hybridization of the atoms involved.

### Step 2: Analyze the Reaction with HCl
When borazine reacts with HCl, it can undergo protonation. The HCl dissociates into \( H^+ \) and \( Cl^- \). The \( H^+ \) ion can add to the borazine structure.

**Hint:** Consider how the \( H^+ \) ion interacts with the borazine structure. Look for sites of negative charge or electron density.

### Step 3: Identify the Protonation Site
In the borazine structure, nitrogen atoms are more electronegative than boron atoms. This means that nitrogen atoms can carry a partial negative charge, making them more likely to attract the \( H^+ \) ion. Thus, protonation will occur at the nitrogen atom.

**Hint:** Recall the concept of electronegativity and how it influences protonation. The more electronegative atom is usually where protonation occurs.

### Step 4: Write the Product of the Reaction
After protonation at the nitrogen atom, the structure of the compound changes. The resulting compound can be represented as \( B_3N_3H_9Cl_3 \), indicating that three hydrogen atoms have been replaced by three chloride ions from the three moles of HCl.

**Hint:** Keep track of the number of hydrogen and chlorine atoms in the final product to ensure the reaction is balanced.

### Step 5: Conclusion
The protonation occurs specifically at the nitrogen atoms in the borazine structure, leading to the formation of the compound \( B_3N_3H_9Cl_3 \).

**Final Answer:** The protonation occurs at the nitrogen atom.