In the vapor phase, BeCl₂ exists as a discrete molecule. (c) On the basis of the formal charges, which Lewis structure is expected to be dominant for BeCl₂?

Verified step by step guidance

1. insert step 1> Determine the total number of valence electrons for BeCl_2. Beryllium (Be) has 2 valence electrons, and each chlorine (Cl) has 7 valence electrons.
2. insert step 2> Calculate the total number of valence electrons by adding the valence electrons of Be and the two Cl atoms.
3. insert step 3> Draw the Lewis structure for BeCl_2 by placing Be in the center and connecting it to each Cl atom with a single bond.
4. insert step 4> Assign formal charges to each atom in the structure. The formal charge is calculated using the formula: Formal Charge = (Valence electrons) - (Non-bonding electrons) - 0.5*(Bonding electrons).
5. insert step 5> Evaluate the formal charges to determine the dominant Lewis structure. The structure with formal charges closest to zero is typically the most stable and dominant.

Key Concepts

Lewis Structures

Lewis structures are diagrams that represent the bonding between atoms in a molecule and the lone pairs of electrons that may exist. They help visualize the arrangement of electrons and the connectivity of atoms, allowing chemists to predict molecular geometry and reactivity. In the case of BeCl2, drawing the Lewis structure involves placing the valence electrons around the beryllium and chlorine atoms to satisfy the octet rule where applicable.

Formal Charge

Formal charge is a theoretical charge assigned to an atom in a molecule, calculated based on the number of valence electrons, the number of non-bonding electrons, and the number of bonds. It helps determine the most stable Lewis structure by minimizing the formal charges across the molecule. For BeCl2, analyzing the formal charges of different Lewis structures can indicate which structure is more favorable and likely to be the dominant form.

Molecular Geometry

Molecular geometry refers to the three-dimensional arrangement of atoms within a molecule. It is influenced by the number of bonding pairs and lone pairs of electrons around the central atom, which can affect the molecule's shape and properties. In BeCl2, understanding its linear geometry is crucial for predicting how the molecule interacts with other substances and its overall stability.