Robert Boomer
Bronte Richardson
Jacob Bardwell
Jeff Polasz


Structure and Functional
Groups: Slides 3-5

Nomenclature: Slides 6-9

Properties/Uses: Slides 10-12

Examples: Slides 13-14

Reactions: Slides 15-20

Structure & Functional Group
Functional Group:

Carboxylic acids contain a carbonyl attached to a hydroxyl group; this is called a carboxyl group


Carboxyl group is defined by the double bond between carbon and oxygen
R represents the carbon chain

Structure & Functional Group


They are Brønsted-Lowry acids because they are proton (H+) donors which makes them more acidic than alcohol
Acids with two or more carboxyl groups are called dicarboxylic, tricarboxylic, etc.

Structure & Functional Group
Differences:

Quiz



What functional group do carboxylic acids have?
Why are carboxylic acids more acidic than alcohol?
What is the difference between a carboxylic acid and a ketone?

Nomenclature
Step 1:

Identify longest carbon chain (gives you prefix)

Begin at carbon that has the hydroxide and oxygen atoms bonded to it
Step 2:

Determine whether there are any double or triple bonds present

Nomenclature
Step 3:

Apply suffix –oic acid to the prefix determined by parent chain
Step 4:

Identify the presence of any branches (ethyl,
 methyl, propyl, etc.)
Identify and record at which branch each meets the parent chain
REMINDER: CARBOXYL GROUP ALWAYS TAKE
PRESIDENCE WHEN NAMING A MOLECULE

Nomenclature Practice
Name the following carboxylic acids:

Nomenclature Practice
Draw the following carboxylic acids:

3-Methylbutanoic Acid

4-chloro-2-methyl-3-pentynoic acid

Properties
Acidity

Given by the name, Carboxylic acids are acidic. This is because of the transfer of the hydrogen ion present in the -COOH group, to a water molecule, ionizing the acid molecule

Properties
Example 1:
𝑪𝑯𝟑𝑪𝑶𝑶𝑯 + 𝑯𝟐𝑶 ↔ 𝑪𝑯𝟑𝑪𝑶𝑶 − + 𝑯𝟑𝑶 −
(Above: Ethanoic acid, a weak acid)

Carboxylic acids are relatively weak compared to other acids because they do not fully dissociate to produce H+ cations however are still the most acidic out of the organic functional groups.

Properties
Solubility

The hydrogen bonds, as well as the presence
 of a carbonyl group (-CO) both result in the molecules being polar, preforming similar solubility behaviour as alcohols.
Carboxylic acids containing up to four carbon atoms will mix with water in any proportion, whereas larger hydrocarbon chains are more likely to be insoluble because they are more non-polar. However this means they can react with organic bases to produce organic salts.

Properties
Melting/Boiling Point

Carboxylic acids have higher boiling points than their parent alkanes due to the fact that the carboxyl group has increased intermolecular attractions from the high polarity of the molecule

Properties
Example 2: Oxalic acid, similar to Ethanoic acid, has 2 carbon atoms and unlike
Ethanoic acid, has 2 carboxyl groups. This increases the boiling point considerably because it is able to donate a proton twice, doubling the size of the molecule and increasing Vander Waal forces, therefore the boiling point.

Oxalic acid (189◦C)



Uses
Carboxylic acids are generally characterized by their distinctive smell or sour/tangy taste.
They are found in citrus filled fruits such as apples, rhubarb, grapes and other fruits with high acidity
Carboxylic acids are also produced when an alcohol is oxidized accordingly. This creates the double bond between the oxygen, creating the –COOH group. An example of this is when red wine is oxidized to make red wine vinegar, gaining the more sour taste.

Uses

Carboxylic acids are also very useful when acting as precursors for producing other compounds due to the fact that they can undergo ionization, oxidization, react in neutralization reactions with alcohols and organic bases to form biological compounds.

Common Carboxylic Acids
Citric Acid Ascorbic acid
(Vitamin C)
Lactic Acid
Tartaric acid
Formic acid
(methanoic acid)

Quiz 2




True or False: Carboxylic acids are acidic because of condensation.
Which Organic Family do Carboxylic acids have similar solubility as?
True or False: Carboxylic acids have a high boiling point.
What do alcohols undergo to produce
Carboxylic acids?

Reactions
Controlled Oxidization (Preparation)
Conditions:


Aqueous solutions
Requires Catalyst: Usually K2Cr2O7 (Potassium




 dichromate (VI))
A carboxylic acid is formed from a controlled oxidation of an aldehyde
Mild oxidation  Aldehyde
Further controlled oxidation  Carboxylic Acid
Functional group: carboxyl group (One additional
O atom)
Add an O to the H to make OH

Reactions
Formation of an aldehyde:
Formation of a carboxylic acid:

Reactions
Example 1: Methanoic Acid
Methanal
(Formaldehyde)
+ (O) 
Methanoic Acid
(Formic Acid)

Reactions
Example 2: Breathalyzer (Oxidation of ethanol to acetic acid)
Ethanol + (O)  Ethanal (Acetaldehyde) +
(O)  Acetic Acid
+ Cr⁶⁺ (orange)  + Cr³⁺ (green)

Reactions



When measured volume of air containing ethanol passes through breathalyzer tube, ethanol is oxidized to acetaldehyde (ethanol) then to acetic acid.
This process is accompanied by a reduction of the chromate ion to its Cr³ ⁺ oxidation state.
The extent of the green colour down the breathalyzer tube provides a measure of the concentration of alcohol in the breath.

Reaction Worksheet