CARBOXYLIC ACIDS REACTIONS
presented by:
Mizgin Q.Abdullah
Atoor Taweer
Karzan Muhemmed
Data: 14\4\2019
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Introduction:
carboxylic acid :is an organic compound that contains a carboxyl
group (C(=O)OH).[1] The general formula of a carboxylic acid is R–COOH,
with R referring to the rest of the (possibly quite large) molecule. Carboxylic
acids occur widely. Important examples include the amino acids(which
make up proteins) and acetic acid (which is part of vinegar). Deprotonation
of a carboxyl group gives a carboxylate anion. Important carboxylate salts
are soaps. Carboxylic acids are commonly identified by their trivial names.
They often have the suffix -ic acid. IUPAC-recommended names also exist;
in this system, carboxylic acids have an -oic acid suffix.[2] For
example, butyric acid (C3H7CO2H) is butanoic acid by IUPAC guidelines.
For nomenclature of complex molecules containing a carboxylic acid, the
carboxyl can be considered position one of the parent chain even if there
are other substituents, for example, 3-chloropropanoic acid. Alternately, it
can be named as a "carboxy" or "carboxylic acid" substituent on another
parent structure, for example, 2-carboxyfuran.
The carboxylate anion (R–COO− or RCO2-) of a carboxylic acid is usually
named with the suffix -ate, in keeping with the general pattern of -ic
acid and -ate for a conjugate acid and its conjugate base, respectively. For
example, the conjugate base of acetic acid is acetate.
This experiment is in two parts. The first is a synthesis of Benzocaine, in which
you convert a carboxylic acid to one of its derivatives, an ester. The second part
consists of a couple of simple test tube reactions that illustrate some of the
properties of carboxylic acids and various derivatives.
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Straight-chain, saturated carboxylic acids
Carbo
Common IUPAC Chemical
n Common location or use
name name formula
atoms
Carbonic Carbonic Blood and tissues (bicarbonate buffer
1 OHCOOH
acid acid system)
Methanoic
1 Formic acid HCOOH Insect stings
acid
Ethanoic
2 Acetic acid CH3COOH Vinegar
acid
Propionic Propanoic Preservative for stored grains, body
3 CH3CH2COOH
acid acid odour, milk, butter, cheese
Butanoic
4 Butyric acid CH3(CH2)2COOH Butter
acid
Pentanoic
5 Valeric acid CH3(CH2)3COOH Valerian
acid
Hexanoic
6 Caproic acid CH3(CH2)4COOH Goat fat
acid
Heptanoic
7 Enanthic acid CH3(CH2)5COOH Enantic (vine blossom)
acid
Octanoic
8 Caprylic acid CH3(CH2)6COOH Coconuts
acid
Pelargonic Nonanoic
9 CH3(CH2)7COOH Pelargonium
acid acid
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AIM of experiment:
to conduct a preparative synthesis, isolation, and characterization of an
ester and to examine the reactions of an acid chloride with water and
ammonia. In view to this. to be able (1) to determine the acidity of
carboxylic acids; (2) to distinguish a carboxylic acid in another compound
through its solubility; and (3) to recognize the properties of the carboxylic
derivatives.
Apparatus:
Test tube
Cold water
NaoH
pH paper
ammonia acetate
acetamid
H2SO4
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Hot plat
PROCEDURE :
Part A- Carboxylic Acid Salts
. I. Salt Formation
In each of two test tubes, place 0.1 g of benzoic acid. To one tube, add 3 ml of
cold water, to the other, add 3 ml of 10% sodium hydroxide solution. Shake both
tubes, observe, record the result, and write a complete reaction.
II. Salt Hydrolysis
This hydrolysis can be demonstrated by testing the salt solution with litmus
paper. Dissolve approximately 0.2 g of sodium acetate in 5 ml of distilled water.
Test the resulting solution with litmus paper, and note the results. Wash the
aqueous solution down the sink with plenty of water. Record the result, and write
a complete reaction.
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PART B. Esters - Preparation of Methyl Salicylate (Oil of Wintergreen)
I. Dissolve 0.5 g of salicylic acid in 5 ml of methanol in a small beaker. Cautiously,
with constant stirring,
2. Add 10 drops of concentrated sulfuric acid to the mixture. Heat the mixture on
the steam bath for 10 min, then pour it over about 10 g of ice in a small beaker.
3. Stir well and cautiously observe the odor of the product by gently wafting the
vapors toward your nose.
4. Record the result, and write a complete reaction.
5. Add drop-by-drop 1 ml (~ 20 drops) of acetyl chloride to 1 ml of butanol. Allow
to stand for about 2 minutes and then pour carefully into 5 ml of water (acetyl
chloride reacts vigorously with water). Note: the odor of solution by wafting the
smell toward your nose. Remove a little of the insoluble layer with a dropper and
test its solubility in 5% NaOH solution.
PART C. Amides: Hydrolysis of an Amide
Add 0.5 g of acetamide to 5 ml of 10% sodium hydroxide solution in a test tube,
and gently warm the solution, and heat the mixture to boiling. Note the odor of
the evolved gas by gently wafting its vapors toward your nose. Test the gas by
holding a piece of moist red litmus paper in the mouth of the tube. Repeat the
experiment with 0.5 g of acetamide and 5 ml of 10% sulfuric acid. Record the
result, and write a complete reaction(s).
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Discussion:
Salt Formation:we
Salt hydrolysis:
Hydrolysis of an Amide:
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Laboratory Questions:
Write a complete reaction of succinic acid and acetic anhydride?
Answer:
Explain why acetyl chloride is hydrolyzed faster than benzoyl chloride.?
Answer:
because there’s a strong resonance n benzoyl chloride so that can't easily loose
electrons......
Write an equation for the reaction of n-butyl alcohol with acetyl chloride. What
gas evolved?
Answer:
CH3COCl + C4H9OH CH3COO C4H9+ HCl
HCl is the gas that evolved and the product that is produced is n-butanoyl acetate
(ethanoate).
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Write an equation for the reaction of aniline with acetic anhydride?
Answer:
The reaction products are acetyl aniline and acetic acid
C6H5-NH2 + (CH3CO)O = C6H5-NH-CO-CH3 + CH3-COOH
Name two dicarboxylic acids and draw their structures?
Answer:
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methanoic acid (CH2O2)
HCOOH
propanoic acid (C3H6O2)
CH3CH2COOH
What is the difference between Hydrolysis and Dehydration?
• Dehydration is the condition of having less amount of water than the
normal level.
• Hydrolysis is a reaction where a chemical bond is broken using a water
molecule.
• Dehydration affects hydrolysis reactions because for the hydrolysis
reactions to take place there should be water.
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Reference:
1. http://employees.oneonta.edu/knauerbr/chem226/226expts/226_expt08_pro
.pdf
2. https://instruct.uwo.ca/chemistry/283g/labs/Experiment%203/Lab%203-
Oxidation%20of%20an%20Alcohol.pdf
3. https://www.differencebetween.com/difference-between-hydrolysis-and-vs-
dehydration/
4. https://www.chegg.com/homework-help/questions-and-answers/write-
balanced-equation-reaction-involved-synthesis-acetanilide-aniline-acetic-
anhydride-q1205602
5. http://employees.oneonta.edu/knauerbr/chem226/226expts/226_expt08_pro
.pdf
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