Ch.8 - Basic Concepts of Chemical Bonding

Problem 67c

Chapter 8, Problem 67c

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

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.

insert step 2> Calculate the total number of valence electrons by adding the valence electrons of Be and the two Cl atoms.

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.

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).

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.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

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.

Recommended video:

Guided course

01:33

Molecular Geometry with Two Electron Groups

Related Practice

Textbook Question

Draw the Lewis structures for each of the following molecules or ions. Identify instances where the octet rule is not obeyed; state which atom in each compound does not follow the octet rule; and state how many electrons surround these atoms: a. NO, b. BF₃, c. ICl₂⁻, d. OPBr₃ (the P is the central atom), e. XeF₄.

Textbook Question

In the vapor phase, BeCl₂ exists as a discrete molecule. (a) Draw the Lewis structure of this molecule, using only single bonds. Does this Lewis structure satisfy the octet rule?

Textbook Question

(a) Describe the molecule xenon trioxide, XeO3, using four possible Lewis structures, one each with zero, one, two, or three Xe¬O double bonds. (b) Do any of these resonance structures satisfy the octet rule for every atom in the molecule? (c) Do any of the four Lewis structures have multiple resonance structures? If so, how many resonance structures do you find? (d) Which of the Lewis structures in part (a) yields the most favorable formal charges for the molecule?

Textbook Question

There are many Lewis structures you could draw for sulfuric acid, H₂SO₄ (each H is bonded to an O). (a) What Lewis structure(s) would you draw to satisfy the octet rule?

Textbook Question

There are many Lewis structures you could draw for sulfuric acid, H2SO4 (each H is bonded to an O). (b) What Lewis structure(s) would you draw to minimize formal charge?

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 video answer for a similar problem:

Key Concepts

Lewis Structures

Formal Charge

Molecular Geometry

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?