VSEPR Theory Examples: Predicting Molecular Geometry for Common Molecules

📚 Quick Study Guide

• ⚛️ VSEPR theory predicts molecular geometry based on minimizing electron pair repulsion around a central atom.
• 🤝 Electron pairs can be bonding pairs (single, double, or triple bonds) or lone pairs.
• 📐 Geometry is determined by the number of bonding pairs and lone pairs.
• 📝 Common geometries include linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral.
• 🔑 Lone pairs exert greater repulsion than bonding pairs, affecting bond angles.
• 🧮 Use the $AX_mE_n$ notation, where A is the central atom, X is the number of bonding pairs, and E is the number of lone pairs.

🧪 Practice Quiz

1. Which of the following molecules is linear?
   1. A. $H_2O$
   2. B. $CO_2$
   3. C. $NH_3$
   4. D. $SO_2$
2. What is the molecular geometry of $BF_3$?
   1. A. Tetrahedral
   2. B. Trigonal pyramidal
   3. C. Trigonal planar
   4. D. Bent
3. What is the molecular geometry of $CH_4$?
   1. A. Trigonal planar
   2. B. Tetrahedral
   3. C. Bent
   4. D. Linear
4. What is the molecular geometry of $NH_3$?
   1. A. Tetrahedral
   2. B. Trigonal pyramidal
   3. C. Trigonal planar
   4. D. Bent
5. What is the molecular geometry of $H_2O$?
   1. A. Linear
   2. B. Trigonal planar
   3. C. Tetrahedral
   4. D. Bent
6. What is the molecular geometry of $PCl_5$?
   1. A. Tetrahedral
   2. B. Trigonal bipyramidal
   3. C. Octahedral
   4. D. Square planar
7. What is the molecular geometry of $SF_6$?
   1. A. Tetrahedral
   2. B. Trigonal bipyramidal
   3. C. Octahedral
   4. D. Square planar