Which one of the following is the correrct statement ?

Options

A. `B_(2)H_(6).2 NH_(3)` is known as 'inorganic benzen'
B. Boric acid is a protonic acid.
C. Beryllium exhibits coordinates number of six.
D. Chlorides of both coordinates and aluminium have bridged chlorine structure in solid phase.

Explanation

To determine which statement is correct among the given options, we will analyze each statement one by one.

### Step 1: Analyze Option 1
**Statement:** B2S6.2N3 is known as inorganic benzene.

**Analysis:**
- Inorganic benzene typically refers to compounds like B3N3S6, which is indeed analogous to benzene (C6H6) but consists of boron, nitrogen, and sulfur.
- The given formula B2S6.2N3 does not correspond to the commonly accepted structure of inorganic benzene.

**Conclusion:** This statement is **incorrect**.

### Step 2: Analyze Option 2
**Statement:** Boric acid is a protogenic acid.

**Analysis:**
- Boric acid (H3BO3) does not ionize in water to release protons (H+). Instead, it acts as a Lewis acid by accepting hydroxide ions (OH-) to form B(OH)4-.
- Therefore, it does not behave as a protogenic acid, which is defined as a substance that donates protons.

**Conclusion:** This statement is **incorrect**.

### Step 3: Analyze Option 3
**Statement:** Beryllium exhibits a coordination number of 6.

**Analysis:**
- Beryllium (Be) typically has a coordination number of 4 in its compounds due to its electron configuration and bonding characteristics.
- It does not exhibit a coordination number of 6.

**Conclusion:** This statement is **incorrect**.

### Step 4: Analyze Option 4
**Statement:** Chlorides of both beryllium and aluminum have a bridged chlorine structure in their solid state.

**Analysis:**
- Beryllium chloride (BeCl2) in the solid state exists in a polymeric form with a bridged structure.
- Aluminum chloride (AlCl3) dimerizes to form Al2Cl6, which also has a bridged structure.
- Both compounds exhibit a bridged chlorine structure in their solid states.

**Conclusion:** This statement is **correct**.

### Final Answer
The correct statement is: **Chlorides of both beryllium and aluminum have a bridged chlorine structure in their solid state.**

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