Question

The structures of beryllium chloride in solid state and vapour phase, are :

• A. Chain and dimer, respectively
• B. Linear in both
• C. Dimer and Linear, respectively
• D. Chain in both

Answer 1

The Correct Option is A

The question is about the structure of beryllium chloride (BeCl₂) in its different states: solid and vapor. To answer this, we must understand the bonding and structure of BeCl₂ based on its chemical properties.

1. Solid State Structure:
   • In the solid state, beryllium chloride forms a polymeric chain structure. This happens because beryllium seeks to achieve a more stable electronic configuration by sharing electrons with additional chlorine atoms. This leads to the formation of a zigzag polymer type chain in the solid state.
2. Vapor Phase Structure:
   • In the vapor phase, beryllium chloride exists as a dimer, Be₂Cl₄. This occurs because, in the gas phase, the molecule forms bridge bonds between beryllium and chlorine, creating a dimeric structure. This dimer formation helps stabilize the molecule by overcoming the limitations of beryllium having only two valence electrons available for bonding.

Thus, the structures of beryllium chloride in the solid and vapor phases are a chain and a dimer, respectively.

Let's evaluate the given options:

• Chain and dimer, respectively: This is the correct answer, as explained above.
• Linear in both: Beryllium chloride does not form a linear structure in either state.
• Dimer and Linear, respectively: The compound forms a chain in the solid phase, not a dimer.
• Chain in both: The compound forms a dimer in the vapor phase, as opposed to a chain.

 

Therefore, the correct answer is: Chain and dimer, respectively.