Determine the electron and molecular geometries of each of the following molecules. For those with more than one central atom, indicate the geometry about each central atom. (Enter your answers in the order given in the skeletal structure from left to right.)
CH3OH (skeletal structure H3COH)
a) Carbon
b) Oxygen
thanks:)
I don't get how to the structure and how to find oxygen separetley
I know carbon is tetrahedral but i don't know oxygen
To determine the electron and molecular geometries of each atom in CH3OH (also represented as H3COH), we can follow a step-by-step approach:
a) Carbon:
1. Begin by drawing the Lewis structure of CH3OH:
- Carbon is the central atom since it is less electronegative than oxygen and hydrogen.
- The skeletal structure shows a carbon atom bonded to three hydrogen atoms (H3) and an oxygen atom (O).
- The oxygen atom has two lone pairs of electrons.
H H
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H-C-O-H
2. Count the total number of valence electrons:
- Carbon contributes four valence electrons.
- Each hydrogen contributes one valence electron.
- Oxygen contributes six valence electrons.
Total valence electrons = 4 + (1x3) + 6 = 13
3. Calculate the number of electron pairs (both bonding and lone pairs):
- Each bond (covalent or single bond) consists of one electron pair.
- Each lone pair of electrons also counts as one electron pair.
In CH3OH, there are:
- 4 bonding electron pairs (between carbon and hydrogen)
- 2 lone pairs of electrons on the oxygen atom
4. Determine the electron geometry (arrangement of electron pairs around the central atom):
- In this case, carbon has four bonding electron pairs and zero lone pairs.
- This results in a tetrahedral electron geometry.
5. Determine the molecular geometry (arrangement of atoms around the central atom):
- In CH3OH, carbon is bonded to three hydrogen atoms and one oxygen atom.
- The presence of one lone pair of electrons on the oxygen atom affects the molecular geometry.
- The bonding angle between the hydrogen atoms is ~109.5° due to the tetrahedral electron geometry.
- However, the presence of the lone pair on oxygen causes the molecule to have a bent shape.
Therefore, the molecular geometry of the carbon atom in CH3OH is bent.
b) Oxygen:
1. Oxygen is not a central atom in this molecule, but it is connected to carbon, so we can determine its electron and molecular geometries as well.
2. Since oxygen has six valence electrons and is not bonded to any other atoms, it has two lone pairs of electrons.
3. The presence of two lone pairs on oxygen results in an electron geometry of bent.
4. The molecular geometry of oxygen in CH3OH is also bent due to the lone pairs, similar to carbon.
In summary:
a) Carbon in CH3OH has a tetrahedral electron geometry and a bent molecular geometry.
b) Oxygen in CH3OH also has a bent electron and molecular geometry.