Carboxylic Acids

Question 1

Carboxylic Acid

Answer 1

Contains both a carbonyl group and a hydroxyl group bonded to the same carbon

one of the most oxidized functional groups and are always terminal

Question 2

Nomenclature

Answer 2

adding the suffix -oic acid to the parent root when the carboxylic acid is highest priority

ex: 2-methylpentanoic acid

for cyclic carboxylic acids, list the cycloalkane with the suffic carboxylic acid

ex: 1-chloro-2methylcyclopentane carboxylic acid

Salt of carboxylic acids are named with cation, the name of acid with endint -oate

ex: sodium hexanoate

Question 3

Common Names

Answer 3

Methanoic Acid = Formic Acid

Ethanoic Acid = Acetic Acid

Propanoic Acid - propionic acid

Question 4

Dicarboxylic Acids

Answer 4

have a carboxylic acid group on each end of the molecule

suffic is -dioic acid

ex: ethanedioic acid

Question 5

Physical Properties: Hydrogen Bonding

Answer 5

they are polar due to the the carbonyl group and can form H bonds because they have a hydroxyl group

strong intermolecular forces due to both the hydroxyl oxygen and the carbonyl oxygen making H bonds which allow for DIMER production

allow for increased boiling and melting points past their corresponding alcohols

Question 6

Dimer

Answer 6

molecules connected by 2 H bonds

Question 7

Physical Properties: Acidity

Answer 7

hydroxyl hydrogen is very acidic and can lead to neagtive charge that is reinforced by resonance via removal of the hydrogen

this delocalization of the negative charge produces a stable carboxylate anion

the mroe stable the conjugate base (in this case the carboxylate anion), the easier it is for th proton to leave and therefore the stronger the acid!

but still nothing compared to HCl or HSO4-

Question 8

Substituents on carbon atoms near a carboxyl group influence anion stability/acidity. Groups like -NO2 or halides are _______ and increase ______ . In contrast, -NH2 or -OCH3 are _______ group that destabilize the negative charge and decrease _______.

The closer the group is, the mroe of an effect there will be.

Answer 8

electron withdrawing

increase acidity

electron donating

acidity

Question 9

In dicarboxylic acids, each COOH group influences the other. As they are electron withdrawing, dicarboxylic groups are more _______ compared to monocarboxylic acids.

However when a proton is removed, the carboxylate anion is formed ad causes an immediate ____ in acidity of the remaining carboxylic acid. Because if the other H were to go, two negative charges would be around unstable.

Hence the second hydrogen is less ___ and harder to remove for dicarboxylic comapred to monocarboxylic.

Answer 9

acidic

decrease

acidic

Question 10

B dicarboxylic acids

Answer 10

each carboxylic acid is positioned on the B carbon of the other (one carbon between them)

have highly acidic alpha hydrogens

Question 11

Carboxylic acids can be prepared via ____ of aledhydes and primary alcohols.

Answer 11

oxidation

Question 12

Second and tertiary alcohols ______ be oxidized to carboxylic acids because they have atleast _____ bonds to other carbons

Answer 12

cannot

two

Question 13

Oxidizing Agents

Answer 13

Dichromate Salt

Chromium Trioxide

Potassium Permanganate

Question 14

Nucelophilic Acyl Subsitution

Answer 14

1) Nucelophile opens carbonyl producing O- and form tetrahedral intermediate
2) tetrahedral goes back to forming carbonyl and kicks off the leaving group which is the acyl derivative

Question 15

Acyl Derivative

Answer 15

all molecules with a carboxylic acid derived carbonyl

carboxylic acids, amides, esters, anhydrives, and others

Question 16

Good Leaving Group

Answer 16

weakbases (conjugates of stron bases)

Question 17

Carboxylic acids can be converted into amides if the nucelophile used is ______ in ____ solution forming a _____

Answer 17

NH3 or an amine

acidic or basic solution

amide

Question 18

Amides

Answer 18

replace -oic acid with -amide in name of parent carboxylic acid

alkyl groups on nirtogen are placed at begining of the name with N- prefix

resonance state with delocalization between O and N atoms

Question 19

Cyclic Amides

Answer 19

called lactams

named by replacing oic acid with -lactam

Question 20

Esters

Answer 20

hybrid between carboxylic acid and ether

carboxlic acid + alcohol in acidic conditions

condensation reaction with water as side product

1) carbonyl oxygen is protonated and creates positive charge on carbonyl carbon which takes electrons from pi bond
2) alcohol attacks carbonyl carbon, one OH group leaves,the other becomes double bonded again
3) OH + loses its hydrogen

cyclic esters are called lactones

-oic acid replaced by -lactone

Question 21

Anyhydrides

Answer 21

condensation of two carboxylic acids through nucelophilic acyl substitution
(carbonyl - O - carbonyl

replace -oic acid with -oic anhydride

Question 22

Reduction of Carboxylic Acid

Answer 22

Carboxylic acids reduced to primary alcohols using strong reducing agent like LiAlH4

aldehyde intermediates may form

occurs through nucleophilic addition of hydride to carbonyl group

Question 23

Decarboxylation

Answer 23

complete loss of carboxyl group as CO2 to remove a carbon

B-Keto acids may spontaneously decarboxylate when heated and adds a hydrogen in place

electrophile and nucleophile both in same compound

6 member ring structure occurs and tautomerizes to keto form

Question 24

Saponification

Answer 24

long chain carboxylic acid reacts with sodium or potassiu hydroxide forming a salt known as soap

solvates nonpolar organic compounds in aq solutions as they both contain a nonpolar tail and polar head

soap forms micelles so they can solvate in water by having the nonpolar chains dissolve in the hydrocarbon interior of the micelle and then dissolve in water due to polar heads of micelle