AP Chemistry Questions: Hybridization and Molecular Structure

📚 Quick Study Guide

• ⚛️ Hybridization: The mixing of atomic orbitals to form new hybrid orbitals suitable for the pairing of electrons to form chemical bonds in valence bond theory. Common types include $sp$, $sp^2$, $sp^3$, $sp^3d$, and $sp^3d^2$.
• 📐 Molecular Geometry: The three-dimensional arrangement of atoms in a molecule. It is determined by the number of bonding and non-bonding (lone pairs) electron pairs around the central atom.
• 🌐 VSEPR Theory: Valence Shell Electron Pair Repulsion theory predicts the geometry of molecules based on minimizing the electrostatic repulsion between electron pairs around the central atom.
• 🔗 Sigma ($\sigma$) and Pi ($\pi$) Bonds: Single bonds are $\sigma$ bonds. Double bonds consist of one $\sigma$ and one $\pi$ bond. Triple bonds consist of one $\sigma$ and two $\pi$ bonds.
• ⚡ Formal Charge: Calculated as Valence Electrons - Non-bonding Electrons - (1/2 Bonding Electrons). Helps determine the most stable Lewis structure.
• polar bonds, and the geometry of the molecule.

🧪 Practice Quiz

1. Which of the following molecules has $sp^2$ hybridization?
   1. $BeCl_2$
   2. $H_2O$
   3. $BF_3$
   4. $CH_4$
2. What is the molecular geometry of $NH_3$?
   1. Tetrahedral
   2. Trigonal Planar
   3. Trigonal Pyramidal
   4. Bent
3. How many sigma ($\sigma$) and pi ($\pi$) bonds are in $CO_2$?
   1. 2 $\sigma$ and 2 $\pi$
   2. 1 $\sigma$ and 3 $\pi$
   3. 3 $\sigma$ and 1 $\pi$
   4. 4 $\sigma$ and 0 $\pi$
4. What is the hybridization of the central atom in $XeF_4$?
   1. $sp^3$
   2. $sp^3d$
   3. $sp^3d^2$
   4. $sp^2$
5. Which of the following molecules is nonpolar?
   1. $H_2O$
   2. $NH_3$
   3. $CO_2$
   4. $SO_2$
6. What is the bond angle in a tetrahedral molecule?
   1. 90°
   2. 109.5°
   3. 120°
   4. 180°
7. Which of the following has a linear molecular geometry?
   1. $H_2O$
   2. $SO_2$
   3. $BeCl_2$
   4. $NH_3$