Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Carboxylic Acids: Nomenclature, Structure, Properties, Preparation, and Reactions, Quizzes of Organic Chemistry

Definitions and explanations for various terms related to carboxylic acids, including nomenclature, structure and bonding, physical properties, acidity, salts, preparation methods, and reactions. It covers topics such as carboxyl group hybridization, resonance forms, hydrogen bonding, acidity factors, and common reactions.

Typology: Quizzes

2010/2011

Uploaded on 05/08/2011

mccollum-9
mccollum-9 🇺🇸

4 documents

1 / 2

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
TERM 1
Carboxylic acid nomenclature
DEFINITION 1
For open chain carboxylic acids, counting th e longest continuous carbon
chain that contains the carboxyl group (COO H) as the parent chain and
replacing the e ending of alkane with oic a cid. Because carboxyl group is
always at the end of the chain, it is conside red as C1 and the position of
the carboxyl group does not need to be sp ecified in the name. If there
are other functional groups presents in the molecule, the carboxyl group
outrank the other functional groups. The ot her functional group are
considered as substituents. When carboxy l group is attached to a ring,
the parent ring is named( the final e ending is retained) and the suffix
carboxylic acid is added.
TERM 2
Structure and bonding
DEFINITION 2
In the carboxyl group, C and O on the C=O bond are sp2
hybridized, while the O on OH part is sp3 hybridized.
Carboxyl group has three resonance forms, thus electrons
are delocalized on the COOH group. O atom on the C=O
bond is most electron rich (nucleophilic), while the H on the
OH part is most electron deficient (electrophilic).
TERM 3
Physical properties
DEFINITION 3
Carboxylic acids have higher boiling points than alcohols,
ketones and alkenes due to formation of two hydrogen bonds
between the hydroxyl group of each molecule and the
carbonyl oxygen of the other. Carboxylic acids can form
hydrogen bonds with H2O, thus they have similar solubility in
H2O as alcohols do.
TERM 4
Acidity of carboxylic acids
DEFINITION 4
Carboxylic acids are the most acidic c lass of compounds that
contain only C, H and O. Great acidity of carboxylic acids is
attributed to stabilization of carboxylat e ion (COO-)by inductive
effect of carbonyl group and resonan ce stabilization of carboxylate
ion. Electron-withdrawing sub stituent on the -carbon can help
stabilize the carboxylate ion via induc tive effect and thus increase
the acidity of the carboxylic acid. The acidity of the benzoic acids
with EWG at the ortho position is incre ased comparing to those
with EWG at the meta and para posit ions.
TERM 5
Salts of carboxylic acids
DEFINITION 5
Carboxylic acids can be deprotonated by strong base (NaOH or
KOH) to form carboxylate salts. For low molecular weight acids ,
sodium and potassium carboxylate sa lts are soluble in
water.Unbranched carboxylic acids w ith 12-18 carbons give
carboxylate salts that form micelles i n water, which is the
spherical aggregates with carboxylat e ions (the polar head) on the
outside and nonpolar tails (the R chai n ) on the inside.
pf2

Partial preview of the text

Download Carboxylic Acids: Nomenclature, Structure, Properties, Preparation, and Reactions and more Quizzes Organic Chemistry in PDF only on Docsity!

TERM 1

Carboxylic acid nomenclature

DEFINITION 1

For open chain carboxylic acids, counting the longest continuous carbon

chain that contains the carboxyl group (COOH) as the parent chain and

replacing the e ending of alkane with oic acid. Because carboxyl group is

always at the end of the chain, it is considered as C1 and the position of

the carboxyl group does not need to be specified in the name. If there

are other functional groups presents in the molecule, the carboxyl group

outrank the other functional groups. The other functional group are

considered as substituents. When carboxyl group is attached to a ring,

the parent ring is named( the final e ending is retained) and the suffix

carboxylic acid is added.

TERM 2

Structure and bonding

DEFINITION 2

In the carboxyl group, C and O on the C=O bond are sp

hybridized, while the O on OH part is sp3 hybridized.

Carboxyl group has three resonance forms, thus electrons

are delocalized on the COOH group. O atom on the C=O

bond is most electron rich (nucleophilic), while the H on the

OH part is most electron deficient (electrophilic).

TERM 3

Physical properties

DEFINITION 3

Carboxylic acids have higher boiling points than alcohols,

ketones and alkenes due to formation of two hydrogen bonds

between the hydroxyl group of each molecule and the

carbonyl oxygen of the other. Carboxylic acids can form

hydrogen bonds with H2O, thus they have similar solubility in

H2O as alcohols do.

TERM 4

Acidity of carboxylic acids

DEFINITION 4

Carboxylic acids are the most acidic class of compounds that

contain only C, H and O. Great acidity of carboxylic acids is

attributed to stabilization of carboxylate ion (COO-)by inductive

effect of carbonyl group and resonance stabilization of carboxylate

ion. Electron-withdrawing substituent on the -carbon can help

stabilize the carboxylate ion via inductive effect and thus increase

the acidity of the carboxylic acid. The acidity of the benzoic acids

with EWG at the ortho position is increased comparing to those

with EWG at the meta and para positions.

TERM 5

Salts of carboxylic acids

DEFINITION 5

Carboxylic acids can be deprotonated by strong base (NaOH or

KOH) to form carboxylate salts. For low molecular weight acids,

sodium and potassium carboxylate salts are soluble in

water.Unbranched carboxylic acids with 12-18 carbons give

carboxylate salts that form micelles in water, which is the

spherical aggregates with carboxylate ions (the polar head) on the

outside and nonpolar tails (the R chain ) on the inside.

TERM 6

Carbonic acids

DEFINITION 6

CO2 can dissolve in H2O to give carbonic acid (H2CO3)

Carbonic acid is weakly acidic (pKa = 6.4). Deprotonation

gives rise to bicarbonate ion (HCO3-), then carbonate ion

(CO32-). Acids with pKa < 6.4 can react with NaHCO3 to

evolve CO2.

TERM 7

Preparation of Carboxylic Acids 1-

DEFINITION 7

Side-chain oxidation of alkylbenzenes The benzylic C must have at least one H Oxidation of 10 alcohols The carboxylic acids formed have the same number of C with the alcohols. Oxidation of aldehydes The formed carboxylic acids have the same number of C with the aldehydes. Ozonolysis of alkynes Useful if we start with symmetric alkynes Carboxylation of Grignard reagents The reaction converts an RX to a carboxylic acid with one more carbon than the starting halide. The halide could be 10, 20, 30 , aryl or vinyl halide, but cant contain OH, NH or SH groups. Preparation and hydrolysis of nitriles The reaction converts an RX to a carboxylic acid with one more carbon than the starting halide. The halide can only be methyl, 10 or 20 halides. 30, aryl or vinyl halides dont work. Preparation and hydrolysis of cyanohydrin TERM 8

Reactions of Carboxylic Acids 1-

DEFINITION 8

Reaction with base Reduction with LiAlH4 Formation of acyl chlorides Esterification Mechanism of acid-catalyzed esterification (Fischer Esterification) Protonation of carbonyl group activates carbonyl carbon. Nucleophilic addition of alcohol to protonated carbonyl group forms tetrahedral intermediate. Elimination of water from tetrahedral intermediate restores carbonyl group. Intramolecular ester formation: Lactones Formed by intramolecular esterification in a hydroxy acid compound (contain a hydroxyl group and a carboxylic acid functional group) The reaction is most favorable if the resulting ring is 5 or 6-membered. Decarboxylation Simple carboxylic acids that contain only one CO2H group dont go thermal decarboxylation easily. But for diacids with the two CO2H groups separated by one other carbon or b-keto acids, thermal decarboxylation occurs readily. One carbonyl group assists the loss of CO2 from the CO2H group. The product is a carboxylic acid. The product of decarboxylation of diacids (R = OH) is acids; decarboxylation of b-keto acids (R = alkyl) results in ketones.