AP Chemistry Questions on VSEPR Theory: Ace Your Exam

🧪 Quick Study Guide

• ⚛️ VSEPR theory predicts molecular geometry based on minimizing electron pair repulsion around a central atom.
• 📐 The basic shapes include linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral.
• 👯 Lone pairs repel more strongly than bonding pairs, affecting bond angles.
• 📝 Use the $AX_mE_n$ notation: A = central atom, X = bonding atoms, E = lone pairs.
• 💡 Examples: $CH_4$ (tetrahedral), $NH_3$ (trigonal pyramidal), $H_2O$ (bent).
• 🔑 Molecular geometry names ONLY describe the shape of the atoms, not lone pairs.
• ➕ Hybridization can be determined from the VSEPR shape (e.g., tetrahedral = $sp^3$).

🎓 Practice Quiz

1. Which of the following molecules is linear?
   1. $H_2O$
   2. $CO_2$
   3. $NH_3$
   4. $SO_2$
2. What is the molecular geometry of $BF_3$?
   1. Tetrahedral
   2. Trigonal pyramidal
   3. Trigonal planar
   4. Bent
3. The bond angle in $CH_4$ is approximately:
   1. 90°
   2. 109.5°
   3. 120°
   4. 180°
4. Which molecule has the largest bond angle?
   1. $H_2O$
   2. $NH_3$
   3. $CH_4$
   4. $CO_2$
5. What is the electron domain geometry of $SF_6$?
   1. Tetrahedral
   2. Trigonal bipyramidal
   3. Octahedral
   4. Square planar
6. Which of the following molecules is polar?
   1. $CO_2$
   2. $BF_3$
   3. $CCl_4$
   4. $H_2O$
7. What is the molecular geometry of a molecule with 4 bonding pairs and 2 lone pairs?
   1. Tetrahedral
   2. Square planar
   3. See-saw
   4. Octahedral