CH3-Acids and Bases_BLANKSLIDES
Notes on Acids and Bases (CHEM2070 - Fall 2024)
Page 1: Course Information
Course Title: CHEM2070
Instructor: Dr. Gordon
Semester: Fall 2024
Page 2: Chapter Overview
Chapter 3: Acids and Bases
Page 3: Definitions
Bronsted-Lowry Acid: A substance that donates a proton (H⁺).
Bronsted-Lowry Base: A substance that accepts a proton (H⁺).
Conjugate Acid: Formed when a base gains a proton.
Conjugate Base: Formed when an acid loses a proton.
Page 4: Electron Movement
Bond Formation and Breaking: Involves movement of electrons.
Curved Arrows: Used to illustrate the flow of electron density in reactions.
Page 5: Reaction Mechanisms
Multistep Reaction Mechanism: Identifies steps that involve proton transfers.
Page 6: Acid and Base Strength
Importance of Strength: Helps predict reaction progression.
Quantitative Strength Analysis: Numerical values to assess strength.
Qualitative Strength Analysis: Descriptive assessment of strength.
Page 7: pK_a Values
pK_a Values: Used to determine the strength of acids and their conjugate bases.
Strongest to Weakest Acids: Ranges from H⁻ (strongest) to H₂O (weakest).
Conjugate Base Strength: Corresponds inversely to acid strength.
Page 8: Predicting Equilibria
Using pK_a Values: Predicts the favored direction of acid/base equilibrium.
Page 9: Example of pK_a Application
Example Reaction: H⁺ + OH⁻
pK_a Values: H⁺ = 15.7, OH⁻ = 50.
Page 10: Charge and Acidity
Different Charges: Same atom can have different charges affecting acidity.
Page 11: Comparing Acid Strengths
Relative Strength Determination: Based on the stability of conjugate bases.
Page 12: ARIO Principles
Atoms in the Same Row: Stability increases with electronegativity.
Stability Factors: Volume and concentration of negative charge affect stability.
Page 13: Resonance Stabilization
Resonance: Spreads negative charge across multiple atoms, enhancing stability.
Page 14: Induction Stabilization
Induction: Spreads out formal negative charge, contributing to stability.
Page 15: Orbital Effects
Orbital Type: Affects the stability of formal negative charges.
Page 16: ARIO Order of Importance
Type of atom carrying the charge.
Resonance effects.
Induction effects.
Orbital type where the charge resides.
Page 17: Ranking Acids Using ARIO
Example Rankings: Various acids ranked based on ARIO principles.
Page 18: Exceptions to ARIO
Limitations of ARIO: Some acids require knowledge of pK_a values for accurate ranking.
Page 19: Predicting Equilibrium
Two Methods:
Compare pK_a values of acids.
Assess relative stability of conjugate bases.
Page 20: Counterions in Reactions
Presence of Counterions: Necessary for charge balance in solutions.
Example Reaction: NaNH₂ + H₂O → NH₃ + NaOH.
Page 21: Lewis Acids and Bases
Lewis Acid: Accepts a pair of electrons.
Lewis Base: Donates a pair of electrons.
Overlap with Bronsted-Lowry: All Bronsted acids and bases are also Lewis acids and bases.
Page 22: Lewis Acid/Base Reactions
Electron Sharing: Some reactions cannot be classified under Bronsted-Lowry definitions.
Page 23: Additional Information
Title Text: Further details on the topic may be provided in subsequent sections.