A) Draw The Lewis Dot Structure For The CH2O Molecule (Carbon Is The Central Atom)

6. A) Draw The Lewis Dot Structure For The CH2O Molecule (Carbon Is The Central Atom). B) Determine The Formal Charge On Each Species In The Molecule. C) Draw The Valence Shell Electron Pair Repulsion Sketch And Determine The Electronic And Molecular Geometry For Carbon Dioxide. D) Draw The Valence Bond Sketch And Determine The Bonding Description Of The

The correct answer and explanation is:

A) Lewis Dot Structure for CH2O (Formaldehyde)

In formaldehyde (CH2O), carbon is the central atom, and it is surrounded by two hydrogen atoms and one oxygen atom.

1. Step 1: Count the total number of valence electrons.

• Carbon (C) has 4 valence electrons.
• Hydrogen (H) has 1 valence electron (2 hydrogens = 2 electrons).
• Oxygen (O) has 6 valence electrons.
• Total valence electrons = 4 (C) + 2 (H) + 6 (O) = 12 electrons.

1. Step 2: Place the atoms in the correct arrangement.

• Carbon is the central atom, surrounded by two hydrogen atoms and one oxygen atom.

1. Step 3: Distribute the electrons.

• Carbon forms single bonds with the two hydrogens (2 electrons for each bond).
• Carbon forms a double bond with oxygen (4 electrons). The structure can be drawn as:

    H-C=O
     |
     H

The remaining electrons are placed as lone pairs on oxygen.

B) Formal Charge Calculation

Formal charge is calculated using the formula:

[
\text{Formal charge} = \text{Valence electrons} – (\text{Lone pair electrons} + \frac{\text{Bonding electrons}}{2})
]

For each atom:

• Carbon (C):
• Valence electrons = 4
• Lone pair electrons = 0
• Bonding electrons = 8 (4 electrons from 2 single bonds with H and 4 electrons from the double bond with O)
• Formal charge on carbon = ( 4 – (0 + \frac{8}{2}) = 4 – 4 = 0 )
• Hydrogen (H):
• Valence electrons = 1
• Lone pair electrons = 0
• Bonding electrons = 2 (1 bond)
• Formal charge on hydrogen = ( 1 – (0 + \frac{2}{2}) = 1 – 1 = 0 )
• Oxygen (O):
• Valence electrons = 6
• Lone pair electrons = 4 (2 lone pairs)
• Bonding electrons = 4 (from the double bond with carbon)
• Formal charge on oxygen = ( 6 – (4 + \frac{4}{2}) = 6 – 6 = 0 )

Thus, all atoms have a formal charge of 0, making this a neutral molecule.

C) Valence Shell Electron Pair Repulsion (VSEPR) Sketch for CO2

In CO2 (carbon dioxide), carbon is the central atom, and it forms double bonds with two oxygen atoms. The VSEPR theory predicts the molecular geometry by considering the repulsion between electron pairs.

1. Electron pairs around carbon:

• Carbon has 2 double bonds, and each double bond is considered as one electron pair in VSEPR theory.
• Therefore, carbon has two regions of electron density.

1. Electronic Geometry:

• The electron pairs around carbon will arrange themselves in a linear shape to minimize repulsion.
• Electronic geometry = Linear.

1. Molecular Geometry:

• Since both electron pairs are involved in bonding, the molecular geometry is also linear.

Thus, the electronic and molecular geometry of CO2 is linear.

D) Valence Bond (VB) Sketch and Bonding Description for CO2

In the valence bond theory, bonds are formed by the overlap of atomic orbitals.

1. For CO2:

• The carbon atom uses sp hybridization to form two sigma bonds with the oxygen atoms.
• Each oxygen atom uses sp2 hybridization and overlaps its sp2 orbital with the sp hybrid orbital of carbon to form the sigma bonds.
• The remaining p orbitals on carbon and oxygen overlap to form the pi bonds.

1. Bonding Description:

• In CO2, each C=O bond consists of one sigma bond (from sp and sp2 hybrid orbital overlap) and one pi bond (from p orbital overlap).
• The two sigma bonds are aligned in a straight line, and the pi bonds are formed perpendicular to the sigma bonds.

This gives the molecule a linear structure, with a bond order of 2 for each C=O bond.