Nature of bonding found in vapour phase `AlCl_3` is

Options

A. only covalent
B. Covalent & ionic
C. Covalent & coordinate
D. Only ionic

Answer

To determine the nature of bonding found in the vapor phase of AlCl₃, we can follow these steps:

### Step 1: Understand the Structure of AlCl₃ in Vapor Phase
AlCl₃ (aluminum chloride) exists as a dimer in the vapor phase, which means that two AlCl₃ molecules combine to form Al₂Cl₆.

### Step 2: Analyze the Dimer Structure
In the dimer Al₂Cl₆, we can visualize the arrangement of aluminum and chlorine atoms. Each aluminum atom is surrounded by chlorine atoms, and the overall structure can be represented as follows:

- Each aluminum atom is bonded to three chlorine atoms.
- The dimerization involves the formation of additional bonds between the two aluminum atoms and some of the chlorine atoms.

### Step 3: Identify the Types of Bonds
In the dimer Al₂Cl₆:
- **Covalent Bonds**: These are formed by the equal sharing of electrons between the aluminum and chlorine atoms.
- **Coordinate Bonds**: A coordinate bond (or dative bond) is formed when one atom donates both electrons for the bond. In this case, some of the chlorine atoms donate a pair of electrons to aluminum, forming coordinate bonds.

### Step 4: Conclusion on the Nature of Bonding
Given that AlCl₃ in the vapor phase exists as a dimer (Al₂Cl₆) and contains both covalent and coordinate bonds, we can conclude that the nature of bonding in the vapor phase of AlCl₃ is characterized by both covalent and coordinate bonding.

### Final Answer
The nature of bonding found in the vapor phase of AlCl₃ is **covalent and coordinate bonding**.

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