VSEPR worksheet answers - 1.pdf - | Course Hero - Free Printable

Let’s go through each molecule one by one and fill in the table correctly. We’ll use VSEPR theory to figure out the shape, bond angles, polarity, and hybridization.

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1. BeCl₂

- Lewis structure: Cl–Be–Cl (linear)
- Electron groups around central atom (Be): 2 bonding pairs → 2 electron groups
- Electron geometry: Linear
- Molecular geometry: Linear
- Bond angle: 180°
- Polarity: Nonpolar (symmetrical, dipoles cancel)
- Hybridization: sp (2 electron groups → s + p = sp)

✔ Correct as shown in image.

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2. HCN

- Lewis structure: H–C≡N
- Central atom is C.
- Electron groups on C: 2 (one single bond to H, one triple bond to N counts as 1 group) → 2 electron groups
- Electron geometry: Linear
- Molecular geometry: Linear
- Bond angle: 180°
- Polarity: Polar (N is more electronegative than C, so dipole doesn’t cancel — it’s not symmetrical like CO₂)
- Hybridization: sp

⚠️ Image says “non polar” — that’s wrong! HCN is polar because the dipole from C→N isn’t canceled. The H–C bond has a small dipole too, but overall, the molecule has a net dipole toward N.

So correction: Polar

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3. BF₃

- Boron trifluoride: B with 3 F atoms, no lone pairs.
- Electron groups: 3 bonding → 3 electron groups
- Electron geometry: Trigonal planar
- Molecular geometry: Trigonal planar
- Bond angle: 120°
- Polarity: Nonpolar (symmetrical, all bonds identical, dipoles cancel)
- Hybridization: sp²

✔ Correct as shown.

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4. SO₂

- Sulfur dioxide: S bonded to two O atoms, and S has one lone pair.
- Total electron groups on S: 3 (2 bonding + 1 lone pair) → 3 electron groups
- Electron geometry: Trigonal planar
- Molecular geometry: Bent (because of lone pair)
- Bond angle: Less than 120° (about 119° due to lone pair repulsion)
- Polarity: Polar (bent shape → dipoles don’t cancel)
- Hybridization: sp²

✔ Correct as shown.

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5. CH₂O (formaldehyde)

- Carbon is central: double bond to O, single bonds to two H’s.
- Electron groups on C: 3 (double bond counts as 1 group, plus two single bonds) → 3 electron groups
- Electron geometry: Trigonal planar
- Molecular geometry: Trigonal planar
- Bond angle: ~120°
- Polarity: Polar (C=O bond is very polar, and molecule isn’t symmetrical enough to cancel — H’s are less electronegative, so net dipole toward O)
- Hybridization: sp²

✔ Correct as shown.

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6. NH₃

- Nitrogen with 3 H’s and 1 lone pair.
- Electron groups: 4 (3 bonding + 1 lone pair) → 4 electron groups
- Electron geometry: Tetrahedral
- Molecular geometry: Trigonal pyramidal
- Bond angle: <109.5° (about 107° due to lone pair)
- Polarity: Polar (lone pair makes it asymmetrical)
- Hybridization: sp³

✔ Correct as shown.

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7. SF₄

- Sulfur tetrafluoride: S has 4 F atoms and 1 lone pair.
- Electron groups: 5 (4 bonding + 1 lone pair) → 5 electron groups
- Electron geometry: Trigonal bipyramidal
- Molecular geometry: See-saw (or distorted tetrahedron)
- Bond angles: Axial-equatorial ≈ 90°, equatorial-equatorial ≈ 120° (but distorted)
- Polarity: Polar (asymmetrical due to lone pair)
- Hybridization: sp³d

✔ Correct as shown.

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8. IF₅

- Iodine pentafluoride: I has 5 F atoms and 1 lone pair.
- Electron groups: 6 (5 bonding + 1 lone pair) → 6 electron groups
- Electron geometry: Octahedral
- Molecular geometry: Square pyramidal
- Bond angles: ~90° (between axial and equatorial), but slightly less due to lone pair
- Polarity: Polar (lone pair breaks symmetry)
- Hybridization: sp³d²

✔ Correct as shown.

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Now let’s fix the mistake we found:

➡️ HCN is POLAR, not nonpolar.

All other entries are correct.

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Final Answer:
The only error in the worksheet is for HCN — it should be labeled as Polar, not Nonpolar. All other answers are correct.