CHE-2201 Lecture Notes - Lecture 6: Octet Rule, Leaving Group, Bond-Dissociation Energy
Document Summary
Enthalpy (q or h) is the heat of energy exchange between the reaction and its surroundings at constant pressure. Breaking a bond requires the system to absorb energy. Bonding mo is lower in energy than the antibonding mo. Bonds can break homolytically (breaks down the center and each atom gets an electron) or heterolytically (one atom gets all of the electrons of the bond and the other gets none) Bond dissociation energy (bde) or h for bond breaking generally represents the energy associated with homolytic cleavage. Temperature decreases (endothermic) if energy increases during the reaction, the energy of the product will be higher in regards to the reactants (reactants will be more stable) Pe goes up, stability goes down, and bond strengths decreases. Temperature increases (exothermic) if energy decreases during the reaction, the energy of the the product will be lower in regards to the reactants (products will be more stable)
