Ch. 3 - Acids and BasesWorksheetSee all chapters
All Chapters
Ch. 1 - A Review of General Chemistry
Ch. 2 - Molecular Representations
Ch. 3 - Acids and Bases
Ch. 4 - Alkanes and Cycloalkanes
Ch. 5 - Chirality
Ch. 6 - Thermodynamics and Kinetics
Ch. 7 - Substitution Reactions
Ch. 8 - Elimination Reactions
Ch. 9 - Alkenes and Alkynes
Ch. 10 - Addition Reactions
Ch. 11 - Radical Reactions
Ch. 12 - Alcohols, Ethers, Epoxides and Thiols
Ch. 13 - Alcohols and Carbonyl Compounds
Ch. 14 - Synthetic Techniques
Ch. 15 - Analytical Techniques: IR, NMR, Mass Spect
Ch. 16 - Conjugated Systems
Ch. 17 - Aromaticity
Ch. 18 - Reactions of Aromatics: EAS and Beyond
Ch. 19 - Aldehydes and Ketones: Nucleophilic Addition
Ch. 20 - Carboxylic Acid Derivatives: NAS
Ch. 21 - Enolate Chemistry: Reactions at the Alpha-Carbon
Ch. 22 - Condensation Chemistry
Ch. 23 - Amines
Ch. 24 - Carbohydrates
Ch. 25 - Phenols
Ch. 26 - Amino Acids, Peptides, and Proteins

One of the most challenging aspects of this chapter will be understanding and differentiating between different definitions that all sound kind of similar. We’re gonna move slowly through this, step-by-step.

The Lewis Definition

Concept #1: The Lewis definition of acids and bases.

The Lewis definition is the most general of the definitions that applies to all cases. It’s actually just another name for what we learned earlier as Nucleophiles and Electrophiles.

  • A Lewis Acid is an electron pair ACCEPTOR
  • A Lewis Base is an electron pair DONOR
Brønsted-Lowry Definition

Concept #2: The Bronsted-Lowry definition of acids and bases.

The Brønsted-Lowry definition is a more specific definition that only applies to some acids and bases. In this definition, electrons don’t matter- we only look at protons.

  • A Brønsted-Lowry Acid is a proton DONOR
  • A Brønsted-Lowry Base is a proton ACCEPTOR

Concept #3: Understanding the difference between Lewis and Bronsted-Lowry using 6 examples.

Let’s watch a few examples so you can get the hang of the differences between these definitions:

Heads up: By definition, any Brønsted-Lowry acid is also a Lewis acid. This is because if you are able to donate a proton, you are always able to accept an electron in return!

Concept #4: Using a diagram to understand the difference between Lewis and Bronsted-Lowry definitions.

General Features of Equilibrium

When determining how acids and bases react together, it important to understand the concepts of conjugates and Ke

Concept #5: Equilibrium constant and conjugates.

Drawing Reactions Based on Definitions

Even though we still have no idea what we are doing, we should be able to use patterns of nucleophiles and electrophiles, coupled with what we learned about how to draw arrows for mechanisms, to predict our first acid-base reactions.

Practice: Which of the following compound(s) cannot be characterized as a Lewis acid?

Practice: Which of the following compounds is most likely to have come from the stronger acid?

Additional Problems
Identify the Lewis acid and Lewis base in each of the following reactions.   
Circle the compounds below which can act as Lewis bases and put a box around the compounds which can act as Lewis acids. But first, select only Lewis Bases from the compounds below:
Ethanol is:  A. a catalyst B. a reactive intermediate C. a Brønsted acid D. a Brønsted base 
A Lewis base can also be known as: a) an electrophile b) a nucleophile c) an audiophile
Give the term that best matches the given definition.    a. Bronsted­-Lowry Acid b. Bronsted-­Lowry Base c. Lewis Acid d. Lewis Base e. Electronegativity f. Ionic bond g. Covalent bond h. Polar Covalent bond i. Hydrophobic j. Hydrophilic   1.________: Any species that can accept electrons 2. ________: The ability of an atom to attract the shared electrons in a covalent bond. 3. ________: A compound that can accept a proton.  
Select all the Lewis Acids in the group of compounds below:  
Circle all the Lewis Bases in the group of compounds below and  explain your answer.  
How many atoms and electrons are directly involved in the bond-making and bond-breaking for a Brønsted-Lowry acid-base reaction? (A) four atoms, four electrons (B) four atoms, three electrons  (C) four atoms, two electrons  (D) three atoms, four electrons  (E) three atoms, three electrons  (F) three atoms, two electrons
Fill in the roles (abbreviated in the parentheses) of the reactants in the boxes. Which one is the Lewis base ( B)? Which one is the Lewis acid ( A)?
Identify the Lewis acid: A. AlCl4- B. NH3 C. BCl3 D. CCl4
Identify the Lewis Base: A. B(OH)3 B. NH4+ C. CCl4 D. N(CH3)3
Designate the Lewis acid and Lewis base in each of the following reactions:
Designate the Lewis acid and Lewis base in each of the following reactions:
Designate the Lewis acid and Lewis base in each of the following reactions:
In the reaction below, identify the Lewis acid and the Lewis base. 
Crude extracts from the ginkgo tree, Ginkgo biloba, have been used for centuries to alleviate symptoms associated with asthma. There are four principal components of Ginkgo extracts, called ginkgolide A, B, D, and M. During E. J. Corey’s classic synthesis of ginkgolide B, compound  1 was converted into compound 5 (J. Am. Chem. Soc. 1988, 110, 649–651):(a) Draw the resonance-stabilized anion ( 3) that is expected when compound 1 is treated with LDA (compound 2), which was introduced in Problem 3.69.
What is the definition of a Bronsted acid?What is the definition of a Lewis acid?What is the definition of a Bronsted base?What is the definition of a Lewis base?(True/False) All Bronsted acids are Lewis acids?(True/False) All Lewis acids are Bronsted Acids?What is the definition of an electrophile?What is the definition of a nucleophile?
In the presence of a Lewis acid, compound  1 rearranges, via intermediate 2, to afford compound 3. (b) Draw curved arrows showing how 2 is transformed into 3. (Hint: It may be helpful to redraw  2 in a different conformation.) 
In one step of a recent total synthesis of (-)-seimatopolide A, a potential antidiabetic drug, the following two structures reacted with each other in an acid-base reaction (Tetrahedron Lett. 2012, 53, 5749–5752):(a) Identify the acid and the base, draw the products of the reaction, and show a mechanism for their formation.
Write balanced equations for the ionization of each of the following carboxylic acids in water. Express your answer as a chemical equation.
Write balanced equations for the reaction of each of the following carboxylic acids with KOH. Part A acetic acid Express your answer as a chemical equation. Part B 2-methylbutanoic acid Express your answer as a chemical equation.
What organic product is formed?
Draw the products formed by the following acid-base reaction without consideration of the equilibrium position:  
Draw a structure for the product of the acid-base reaction below.
Draw the organic and inorganic products for the following acid/base reaction. Include charges. 
Draw the major organic product of the reaction shown below.  
Draw the organic and inorganic products for the following acid/base reaction. Include charges.
Draw the structure(s) of the major organic product(s) of the following reaction. 
Provide the major organic product of the following reaction. 
Alcohols can act as either acids or bases, similar to water. In the box below draw the products of the following reaction: 
Which is the strongest base? 
Draw the alkoxide and counterion formed in the following case. Include charges in your answer.
Draw the alkoxide and counterion formed in the following case. Include charges in your answer.
Draw the alkoxide and counterion formed in the following case. Include charges in your answer.
Draw the organic and inorganic products for the following acid/base reaction. Include charges
Draw the structure of the products of the neutralization reaction between methylamine and propanoic acid.
Draw the organic and inorganic products for the following acid/base reaction. Include charges.
Draw the organic and inorganic products for the following acid/base reaction. Include charges.
Draw the organic and inorganic products for the following acid/base reaction. Include charges.
Follow the follow of electrons to predict the products of the reaction
Draw the organic and inorganic products for the following acid/base reaction. Include charges.
Draw the organic and inorganic products for the following acid/base reaction. Include charges.
The structure of the product the reaction shown below is:
Draw the structure of the organic product formed in the reaction of m-cresol with sodium hydroxide.
Draw the alkoxide and counterion formed in the following case. Include charges in your answer.
Draw the organic and inorganic products for the following acid/base reaction. Include charges.
Draw the organic and inorganic products for the following acid/base reaction. Include charges. 
Draw the organic and inorganic products for the following acid/base reaction. Include charges.