The structure of borazine, B₃N₃H₆, is a six-membered ring of alternating B and N atoms. There is one H atom bonded to each B and to each N atom. The molecule is planar. (c) What are the formal charges on the atoms in the Lewis structure from part (b)? Given the electronegativities of B and N, do the formal charges seem favorable or unfavorable? What are the formal charges on the atoms in the Lewis structure from part (b)?

Verified step by step guidance

To determine the formal charges, first draw the Lewis structure of borazine, B3N3H6. In this structure, alternate B and N atoms form a hexagonal ring, with each B and N atom bonded to one hydrogen atom.

Calculate the formal charge for each atom using the formula: Formal Charge = (Valence Electrons) - (Non-bonding Electrons) - 0.5*(Bonding Electrons).

For a boron (B) atom: Boron has 3 valence electrons. In the structure, it forms three bonds (two with nitrogen and one with hydrogen), so it has no non-bonding electrons. Calculate the formal charge using the formula.

For a nitrogen (N) atom: Nitrogen has 5 valence electrons. In the structure, it forms three bonds (two with boron and one with hydrogen), and it has one lone pair (2 non-bonding electrons). Calculate the formal charge using the formula.

Compare the formal charges with the electronegativities of B and N. Boron is less electronegative than nitrogen, so it is more favorable for boron to have a positive formal charge and nitrogen to have a negative formal charge. This distribution aligns with the electronegativity trend, making the formal charges favorable.

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.

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 in determining the most stable Lewis structure by indicating how electrons are distributed among atoms. A formal charge of zero is often preferred for stability, while larger charges can indicate less favorable structures.

Electronegativity

Electronegativity is a measure of an atom's ability to attract and hold onto electrons in a chemical bond. In the context of borazine, boron (B) and nitrogen (N) have different electronegativities, which affects the distribution of electron density in the molecule. Understanding electronegativity is crucial for predicting the polarity of bonds and the overall stability of the molecule based on formal charges.

Lewis Structure

A Lewis structure is a diagram that represents the bonding between atoms in a molecule and the lone pairs of electrons that may exist. It provides a visual representation of how atoms are connected and helps in predicting molecular geometry and reactivity. Analyzing the Lewis structure of borazine is essential for determining formal charges and understanding the molecule's electronic structure.

Recommended video:

Guided course

04:28

Lewis Dot Structures: Ions

Related Practice

Textbook Question

Butadiene, C4H6, is a planar molecule that has the following carbon–carbon bond lengths:

(b) From left to right, what is the hybridization of each carbon atom in butadiene?

Textbook Question

Butadiene, C4H6, is a planar molecule that has the following carbon–carbon bond lengths:

(c) The middle C¬C bond length in butadiene (1.48 Å) is a little shorter than the average C¬C single bond length (1.54 Å). Does this imply that the middle C¬C bond in butadiene is weaker or stronger than the average C¬C single bond?

Textbook Question

The structure of borazine, B₃N₃H₆, is a six-membered ring of alternating B and N atoms. There is one H atom bonded to each B and to each N atom. The molecule is planar. (a) Write a Lewis structure for borazine in which the formal charge on every atom is zero.

Textbook Question

The structure of borazine, B₃N₃H₆, is a six-membered ring of alternating B and N atoms. There is one H atom bonded to each B and to each N atom. The molecule is planar. (e) What are the hybridizations at the B and N atoms in the Lewis structures from parts (a) and (b)? Would you expect the molecule to be planar for both Lewis structures? Would you expect the molecule to be planar for both Lewis structures?

Textbook Question

The highest occupied molecular orbital of a molecule is abbreviated as the HOMO. The lowest unoccupied molecular orbital in a molecule is called the LUMO. Experimentally, one can measure the difference in energy between the HOMO and LUMO by taking the electronic absorption (UV-visible) spectrum of the molecule. Peaks in the electronic absorption spectrum can be labeled as π_2p-π_2p*, σ_s-σ_2s*, and so on, corresponding to electrons being promoted from one orbital to another. The HOMO-LUMO transition corresponds to molecules going from their ground state to their first excited state. (c) The electronic absorption spectrum of the N₂ molecule has the lowest energy peak at 170 nm. To what orbital transition does this correspond?