General Organic Chemistry Lecture Notes

Topics Covered

• Electron Configurations
• Bonding
• Formal Charge

Line Angle Formula

• Represents molecules using angles and lines.
• Each angle or line end typically represents a carbon atom.
• Example: NAD+ (Nicotinamide adenine dinucleotide) uses line angle formula.

Electron Configurations

• NAD+ as an electron carrier in the body.
• Electrons configurations based on periodic table positions.
• Shells and orbitals:
  • 1st shell: 1s orbital (2 electrons)
  • 2nd shell: 1s and 3p orbitals (8 electrons total)
  • 3rd shell: 1s, 3p, and access to 5d orbitals.
• Orbital shapes:
  • S orbitals: spherical, more stable due to volume.
  • P orbitals: elongated figure-eight shape.

Electron Configuration in Elements

• Example: Hydrogen (1s1), Helium (1s2)
• Lithium: 1s2 2s1
• Oxygen (neutral): 1s2 2s2 2p4 (2 bonds typically)
• Florine: 1s2 2s2 2p5 (1 bond typically)
• Carbon: typical (1s2 2s2 2p2) vs. true (1s2 2s1 2p3)

Lone Pairs

• Defined as non-bonding electrons in an orbital.
• Example: Oxygen has 2 lone pairs typically.
• Valence shell electrons determine bonding potential.

Types of Bonds

• Covalent Bonds: Formed between nonmetals (e.g., H₂O)
  • Polar Covalent: Unequal sharing of electrons (e.g., H₂O)
  • Non-polar Covalent: Equal sharing (e.g., Cl₂)
• Ionic Bonds: Formed between metals and nonmetals (e.g., Na⁺ and O²⁻)

Formal Charge

• Calculated using:

  [ \text{Formal Charge} = \text{Valence Electrons} - \text{Lone Pair Electrons} - \frac{1}{2} \times \text{Bonding Electrons} ]

• Example: Nitrogen in NAD+ has a positive charge due to bonding structure.

Practice Problems

• Using academic resources like Khan Academy or textbooks is recommended for practice.

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These notes summarize the key concepts discussed during the lecture on electron configurations, bonding, and formal charges in organic chemistry.