REACCIONES DE ÁCIDOS CARBOXÍLICOS Y

SUS DERIVADOS

INTRODUCTION the double bond was relocated and the

negative charge is distributed between
Carboxylic acids are a group of
the two atoms of oxygen.
compounds, characterized because they
There may be multiple carboxyl groups in
possess a functional group called Group
the same molecule. The number of these
carboxyl or carboxyl group (-COOH). The
groups is indicated by the prefixes di, tri,
Group functional carboxyl coincide on the
tetra, etc. Mono long chain carboxylic
same carbon a hydroxyl group (-OH) and
acids are also called fatty acids.
carbonyl (-C = or). Can be represented
as - COOH or - CO2H. several examples of carboxylic acids are
Carboxylic acids are compounds (Z)-, cis-butenodioico acid, or propanoic
characterized by the presence of the acid dioecious butene or maleic acid,
carboxyl group (-COOH) joined a group acid (E) - dioecious butene or trans-
alkyl or aryl. When the carbonated chain butenodioico acid or fumaric acid, oleic
presents a single group carboxyl acids acid.
are called mono carboxylic or fatty acids, Carboxylic acids can react with alkalis to
are referred to as well since they are result in sales (soaps). Also, when they
obtained by the hydrolysis of fats. react with alcohols give rise to esters.
The first member of the aliphatic series of When the ester link occurs within the
carboxylic acids is the metanoico acid or same molecule a Lactone function
formic acid, this acid is found in nature originates. Two carboxyl groups or a
segregated by the ants to bite. carboxyl group and an inorganic acid
The first member of the aromatic group is may condense (with loss of water) to
the phenyl metanoico or benzoic acid. originate an anhydride.
When the carbonated chain presents two Some examples of derivatives of
carboxyl groups, acids are called di carboxylic acids are:
carboxylic, being the first member of the SOAP, ethyl acetate (ester), anhydride
aliphatic series 1, 2 dioico ethane or ethanolic metanoico, g-butyrolactone
oxalic acid.
Physical properties:
Solubility: The carboxyl group - COOH
THEORETICAL FRAMEWORK
gives polar character acids and allows
Carboxylic acids are oxidation three the formation of hydrogen bonds between
functions, i.e. in a same carbon atom are water molecule and the carboxylic acid
inserted an oxo Group (= or) and a moiety. The presence of two atoms of
hydroxyl group (-OH), forming a carboxyl oxygen in carboxyl group makes it
group. They are named systematically possible that two molecules of acid unite
replacing the ending - or hydrocarbon among themselves by bridge hydrogen
origin by the suffix - OIC, but most have double, forming a cyclic Dimer.
common names enshrined by the use. This makes the first four mono acids
The carboxyl group is responsible for the aliphatic carboxylic completely water
polarity of the molecule and the soluble liquid.
possibility to establish hydrogen bonds. The solubility decreases as the number
The hydroxyl hydrogen can be separated of carbon atoms increases. From twelve-
and the compound behaves as an acid. tone acid or lauric acid, carboxylic acids
This dissociation is favored by the are soft solids, insoluble in water. In the
resonance of the carboxylate ion, since aromatic mono carboxylic acids, the
 REACCIONES DE ÁCIDOS CARBOXÍLICOS Y
SUS DERIVADOS

carbon-carbon ratio is 6:1 which causes B) formation of acid chlorides

the solubility see decreased with respect Example:
to the mono aliphatic carboxylic acids.
Boiling point: Carboxylic acids have
boiling points higher due to the presence Ejemplo:
of double hydrogen bridge
Melting point: Melting point varies
according to the number of carbons,
being high of acetic, and formic acids C) dehydration reaction: the powerful
when compared with propanoic, butyric heating in concentrated acids originates the
acid and valeric of 3, 4 and 5 carbons, respective anhydride:
respectively. After 6 carbons melting
point rises irregularly.
This is due to the increase in the number D) esterification reactions: esters are formed
of carbon atoms to interfere in the on. Reaction of an acid and an alcohol.
association between the molecules. Although the esterification reaction is very
Mono aromatic carboxylic acids are complex, we can consider the following
crystalline solids with high melting points general mechanism.
to aliphatic acids.

Esterification is catalyzed by inorganic acids,

such as the H2S04. Reactivity of R'-OH: 1 ° >
2° > 3 °
E) preparation of carboxylic acids.
-The most direct way to obtain a carboxylic
acid is by vigorous oxidation of primary
alcohols or aldehydes:

Chemical properties:
A) Formation of salts. F) Production of dicarboxylic acids: If the
-Organic acids can react with metals less substituent is a second carboxyl group, have
electronegative forming salts and releasing an acid di carboxyl
hydrogen

-All organic acids; soluble or insoluble in

water, they react with aqueous solutions of
bases, forming soluble salts:
 REACCIONES DE ÁCIDOS CARBOXÍLICOS Y
SUS DERIVADOS

MATERIALES Lighter
6 test tubes

Bath of María
1 spatula

pH indicator paper
Water-ice bath
 REACCIONES DE ÁCIDOS CARBOXÍLICOS Y
SUS DERIVADOS

REAGENTS: 10% calcium chloride: Solid, soluble

in water, hygroscopic white Flake and
Methanol: At room temperature is
toilet. Good capacity of absorption.
presented as a liquid (low density)
Under the insoluble.su formula is
light, colourless, flammable and toxic
CaCl2
which is used as an antifreeze,
solvent and fuel. Its chemical formula toacetic nhidro: is a colorless liquid
is CH3OH (CH4O). that smells strongly of vinegar, acetic
Ethanol: occurs in normal pressure anhydride is corrosive, irritant and
and temperature as a colorless, flammable. Its formula is C4H6O3
flammable liquid with a boiling point of
78.4 ° C.
Aniline: formula C6H5NH2. Slightly
It is a psychoactive substance, and is
yellow liquid of characteristic odor. It
the main type of alcohol present in
is not easily evaporate at room
alcoholic beverages, liquors and
temperature. Aniline is slightly soluble
spirits.
in water and is easily dissolved in
Its chemical formula is CH3-CH2-OH
most organic solvents. Aniline may be
(C2H6O or keeping OH, C2H5OH).
toxic if ingested, inhaled or by skin
25% and 10% NaOH: contact.
At room temperature, sodium EXPERIMENTATION:
hydroxide is a white crystalline solid
1. Added 1 ml of acetic acid in 1
odor that absorbs moisture from the
thousand of distilled water and 5
air (hygroscopic). It is very corrosive.
drops of sodium carbonate is notice
benzoic acid: In normal conditions it is that it emanated background bubbles
a colorless solid with a slight but does not change in temperature.
characteristic odor. It is slightly
2 Add a bit of acid benzoic view the
soluble in cold water but it has good
spatula in 3 ml of distilled water, it
solubility in hot water or organic
was observed that it is not soluble;
solvents.
they do not react.
sodium acetate: White crystalline
3 take a small amount of sodium
powder, odorless. Solubility in water:
acetate with a spatula and add to a
47 g / 100 ml, your formula is
test tube containing 3 mL of water.
CH3COONa
We shake and measure the ph with
sodium nitrate: odorless, colorless the paper Given how much ph = 7
crystals and fuel Higroscopicosno, but
4. place 0.5 g oil in a large test tube
facilitates the combustion of other
and 3 mL of NaOH was added to 25%
sustanciasSolubilidad in water, g/100
and 3 mL of ethanol. It was observed
ml at 25 ° C: 92.1 its formula is
that ethanol is more dense than oil
NaNO3
this less dense than sodium
FAT or oil: flowed thick, non-
hydroxide Warmed up in water bath
flammable, non-toxic.
for 20 minutes, then she is agito to
 REACCIONES DE ÁCIDOS CARBOXÍLICOS Y
SUS DERIVADOS

dissolve fat.
It divided the contents of the tube into
2. What is the role of saline on salt acid and
2 halves A and B
alcohol already formed in hydrolysis?
I will cap A tube and agito for one
minute was allowed to stand and be
measured the time that takes to
R/
disappear the foam and this
compared with 2% of a commercial
detergent solution.
3 What is added on the SOAP solution
Heated tube A and added to a large
calcium chloride?
tube containing 10 mL of aqueous
solution of NaCl at 25% and is agito
for 2 minutes and was observed
R/
separation of SOAP by saline effect,
this compared with 2% of commercial
detergent solution.
4 What conclusions can be drawn with
Took the contents of the tube B and
respect to comparisons made between the
will add 2.5 mL of a 10% CaCl2
saponification of the ester and a commercial
solution is agito mix and see if foam is detergent?
formed. This is compared with the
commercial substance.
5) taking in a 1 mL of anhydrous R/
acetic test tube 1 mL of aniline
mixture turning dark and warmed up
so it is an exothermic reaction. then
warmed up to the boil for 6 minutes in
water bath. Cool the mixture in an icy
bath and is crystalline acetanilide.
Added you water and compare with
the commercial mixture to determine
which to more foam. both made foam
alike.
QUESTIONS.
1 ) order the following compounds according
to their decreasing acidity:

a . acid metanoico
b . propanoic acid
c . acid cloroetanoico BIBLIOGRAPHY
d . benzoic acid
e . p-metilbenzoico acid
REACCIONES DE ÁCIDOS CARBOXÍLICOS Y
SUS DERIVADOS