A Project Work
Submitted to the Radiant Secondary School
National Examination Board
In the partial fulfillment of the requirement of Grade XII of
Science In Chemistry
Submitted by : Rajodhan Nath
Date: 2078/08/15
Group: Bio A
Roll no: 38
Content
A) RECOMMENDATION
B) ACKNOWLEDGEMENT
C) EVALUATION
D) ABSTRACT
1. INTODUCTION
2. THEORY/METHODOLOGY/PROCEDURE
3. PROCEDURE
4. OBSERVATION
5. RESULT
6. REFERENCES
Radiant Secondary School
Mahendranagar, Kanchanpur
RECOMMEDATION
It is to certify that Mr. Rajodhan Nath has carried out the project
work "TO STUDY THE NITROUS ACID TEST FOR PRIMARY,
SECONDARY AND TERTIARY AMINES " under my guidance.
I recommend the project work in the partial fulfillment for the
requirement of Grade XII of Science in Chemistry.
…………......
(Bishan Singh Airee)
Radiant Secondary School
Mahendranagar, Kanchanpur
Date: 2078/08/15
ACKNOWLEDGMENTS
First and foremost, I would like to extend my sincere gratitude to Mr.
Bishan Singh Airee for his constructive comments, valuable suggestions,
and unforgettable guidance. I equally thank him for his kindness,
cooperation, and necessary encouragement.
I would like to thank all of my friends with whom I enjoyed and got
fruitful academic and non- academic supports during this tenure that
boost my work.
Finally, I never miss this opportunity to extend my heartily thank to my
parents and family members, whose immense support in each and every
steps of my life help to reinforce my morale.
Radiant Secondary School
Mahendranagar, Kanchanpur
EVALUATION
….…………………….
Mr Bishan Singh Airee
Department of Chemistry
Date: 2078/08/15
ABSTRACT
With the aim to study about nitrous acid test for primary, secondary and
tertiary amines I have prepared a project work with great consultancy with my
fellow classmates and teacher. By conducting various tests, we came to know
about the reaction of nitrous acid with different classes of amines. We came
to know about the comparative study of basic strength of compounds.
INTRODUCTION
Different classes of amines react with nitrous acid in an ice-cold solution to
give different products. So, this reaction may be the distinctive test for
amines. Nitrous acid is an unstable compound so it is prepared on the spot
by the action of sodium nitrite on dilute hydrochloric acid under cold
conditions.
NaNO2 + HCl → HNO2 + NaCl.
THEORY
REACTION WITH PRIMARY AMINE
The major observation is an outburst of odourless and colourless gas and
nitrogen is given off. Unfortunately, no single equation exists that can be
framed for this reaction since we had lots of various organic products. For
example, you obtain alcohol where the group -NH2 is replaced by OH. Let’s
take 1-aminopropane for example.
CH3CH2CH2NH2 + HNO2 → CH3CH2CH2OH + H2O + N2
The propan- 1- ol will be a single product among many that involve propan 2ol, 1 chloropropane, propene and others.
The nitrogen is given off in quantities as described in the equation. By
measuring the amount of nitrogen formed, this reaction can be used to work
out the amount of amine in the solution.
REACTION WITH SECONDARY AMINE
Secondary aliphatic and aromatic amines react with nitrous acid to give Nnitroso alkyl amines which is insoluble yellow oily liquid layer and is insoluble
in mineral acids. For example:
REACTION WITH TERTIARY AMINE
Tertiary aliphatic amines react with nitrous acid to give water-soluble trialkyl
ammonium nitic salt. The result is different in this case. Here, nothing special
happens and we are left with a colourless solution. There is a formation of an
ion by reaction with an acid present.
For example, triethylamine reacts with nitrous acid in cold and forms
water soluble triethyl ammonium nitrite salt.
PROCEDURE
2-3 drops of liquid amine was dissolved in 2.0 mL of 2.0 M HCl in a small test
tube. Liquid amine was cooled in 5-10 °C in an ice bath and 5 drops of cold
was added to 20% aqueous sodium nitrite solution. The immediate evolution
of a colorless gas (nitrogen) indicated a primary, aliphatic amine. If no gas
was evolved but an insoluble yellow or orange liquid was separated from the
solution, then this was indicative of a secondary aliphatic or aromatic amine.
If no gas was evolved and no yellow liquid separated then this was indicative
that no reaction occurred and the amine tested was a tertiary amine.
Another possibility is that the compound is a primary, aromatic amine. These
form diazonium salts that were stable at low temperatures. If no nitrogen
gas was observed evolving, then a few drops of the cold reaction mixture
was added to a cold solution of 50 mg beta-naphthol in 2 mL of 2.0 M
sodium hydroxide. The formation of an orange/red azo dye indicated a
primary aromatic amine.
OBSERVATION
Nitrous acid on reaction with primary amine to give corresponding alcohol
and nitrogen gas. Similarly, nitrous acid on reaction with secondary amine
give N- nitroso alkyl amines which was insoluble yellow layer and insoluble in
mineral acids. On reaction with tertiary amines nitrous acid give watersoluble trialkyl ammonium nitrate salt.
RESULT
Therefore, after conducting various tests for different classes of amines, we
observed Nitrous acid on reaction with primary amine to give corresponding
alcohol and nitrogen gas. Similarly, nitrous acid on reaction with secondary
amine give N- nitroso alkyl amines which was insoluble yellow layer and
insoluble in mineral acids. On reaction with tertiary amines nitrous acid give
water-soluble trialkyl ammonium nitrate salt.
REFERENCES
[1] B.D. Joshi, R. Mishra, P. Tandon, A. C Oliveira, A. P Ayala (2014),
Nitrous acid Chemical Studies of Structural, Journal of Organic
Structure, 1058, pp. 31-40.
[2] B. D. Joshi, NBO, nitrous acid properties and reactions II,
BIBECHANA 14 (2017) 86-97
[3] B. K. Gautam, N.P Chapagain and S. K. Neupane (2009), Text Book of
Chemistry for Class XII, Nawakala Publication, Kathmandu, Nepal.