NCERT Class 12 Chemistry Amines

Scroll down to download pdf file

NCERT Class 12 Chemistry Aldehydes Ketones and Carboxylic Acids. Download NCERT Chapters and Books in pdf format. Easy to print and read. Copies of these textbooks may be downloaded and used as textbooks or for reference. Refer to other chapters and books at other links (NCERT now providing you soft copies of all textbooks of all subjects from class first to twelfth online).

Amines constitute an important class of organic compounds derived by replacing one or more hydrogen atoms of ammonia molecule by alkyl/aryl group(s). In nature, they occur among proteins, vitamins, alkaloids and hormones. Synthetic examples include polymers, dyestuffs and drugs. Two biologically active compounds, namely adrenaline and ephedrine, both containing secondary amino group, are used to increase blood pressure. Novocain, a synthetic amino compound, is used as an anaesthetic in dentistry. Benadryl, a well known antihistaminic drug also contains tertiary amino group. Quaternary ammonium salts are used as surfactants. Diazonium salts are intermediates in the preparation of a variety of aromatic compounds including dyes. In this Unit, you will learn about amines and diazonium salts.

Amines can be considered as derivatives of ammonia, obtained by replacement of one, two or all the three hydrogen atoms by alkyl and/or aryl groups.

Structure of Amines

Like ammonia, nitrogen atom of amines is trivalent and carries an unshared pair of electrons. Nitrogen orbitals in amines are therefore, sp3 hybridised and the geometry of amines is pyramidal. Each of the three sp3 hybridised orbitals of nitrogen overlap with orbitals of hydrogen or carbon depending upon the composition of the amines. The fourth orbital of nitrogen in all amines contains an unshared pair of electrons. Due to the presence of unshared pair of electrons, the angle C–N–E, (where E is C or H) is less than 109.5°;


Amines are classified as primary (1o), secondary (2o) and tertiary (3o) depending upon the number of hydrogen atoms replaced by alkyl or aryl groups in ammonia molecule. If one hydrogen atom of ammonia is replaced by R or Ar , we get RNH2 or ArNH2, a primary amine (1o). If two hydrogen atoms of ammonia or one hydrogen atom of R-NH2 are replaced by another alkyl/aryl(R’) group, what would you get? You get R-NHR’, secondary amine. The second alkyl/aryl group may be same or different. Replacement of another hydrogen atom by alkyl/aryl group leads to the formation of tertiary amine. Amines are said to be ‘simple’ when all the alkyl or aryl groups are the same, and ‘mixed’ when they are different.


In common system, an aliphatic amine is named by prefixing alkyl group to amine, i.e., alkylamine as one word (e.g., methylamine). In secondary and tertiary amines, when two or more groups are the same, the prefix di or tri is appended before the name of alkyl group. In IUPAC system, amines are named as alkanamines, derived by replacement of ‘e’ of alkane by the word amine. For example, CH3NH2 is named as methanamine. In case, more than one amino group is present at different positions in the parent chain, their positions are specified by giving numbers to the carbon atoms bearing –NH2 groups and suitable prefix such as di, tri, etc. is attached to the amine. The letter ‘e’ of the suffix of the hydrocarbon part is retained. For example, H2N–CH2–CH2–NH2 is named as ethane-1, 2-diamine.


3.1 Write IUPAC names of the following compounds and classify them into primary, secondary and tertiary amines.
(i) (CH3)2CHNH2 (ii) CH3(CH2)2NH2 (iii) CH3NHCH(CH3)2
(iv) (CH3)3CNH2 (v) C6H5NHCH3 (vi) (CH3CH2)2NCH3
(vii) m–BrC6H4NH2
13.2 Give one chemical test to distinguish between the following pairs of compounds.
(i) Methylamine and dimethylamine (ii) Secondary and tertiary amines
(iii) Ethylamine and aniline (iv) Aniline and benzylamine
(v) Aniline and N-methylaniline.
13.3 Account for the following:
(i) pKb of aniline is more than that of methylamine.
(ii) Ethylamine is soluble in water whereas aniline is not.
(iii) Methylamine in water reacts with ferric chloride to precipitate hydrated ferric oxide.
(iv) Although amino group is o– and p– directing in aromatic electrophilic substitution reactions, aniline on nitration gives a substantial amount of m-nitroaniline.
(v) Aniline does not undergo Friedel-Crafts reaction.
(vi) Diazonium salts of aromatic amines are more stable than those of aliphatic amines.

13.5 How will you convert:
(i) Ethanoic acid into methanamine
(ii) Hexanenitrile into 1-aminopentane
(iii) Methanol to ethanoic acid
(iv) Ethanamine into methanamine
(v) Ethanoic acid into propanoic acid
(vi) Methanamine into ethanamine
(vii) Nitromethane into dimethylamine
(viii) Propanoic acid into ethanoic acid?
13.6 Describe a method for the identification of primary, secondary and tertiary amines. Also write chemical equations of the reactions involved.
13.7 Write short notes on the following:
(i) Carbylamine reaction (ii) Diazotisation
(iii) Hofmann’s bromamide reaction (iv) Coupling reaction
(v) Ammonolysis (vi) Acetylation
(vii) Gabriel phthalimide synthesis.
13.8 Accomplish the following conversions:
(i) Nitrobenzene to benzoic acid
(ii) Benzene to m-bromophenol
(iii) Benzoic acid to aniline
(iv) Aniline to 2,4,6-tribromofluorobenzene

Please refer to attached file for NCERT Class 12 Chemistry Aldehydes Ketones and Carboxylic Acids


Click on the text For more study material for Chemistry please click here - Chemistry

Latest CBSE News

  • Its expected that CBSE will release the results for class 10and class 12 board exams by end of next week. The results will be declared by many mediums so that students across the country don’t face any issues regarding accessibility to results due to sudden pressure on CBSE results website like previous years. The Central Board of Secondary Education's CBSE Class 12th result 2018 and CBSE Class...
  •  The government of Delhi has instructed 575 schools to return excess fees charged from parents with 9% interest. The list of the 575 schools is as under. Also, the notice issued by the govt says " In  continuation of orders dated 22.02.2018, 03.07.2017, 01.07.2016, 15.03.2016, 20.10.2015, 21.10.2014 and 28.02.2013 and in  exercise of the powers conferred under  rule   SO(xviii)  j  Section  24(3...
  • CBSE has issued circular explaining the details regarding re evaluation process for class 12 and class 10. Read the details below.. 1. Verification of Marks a)  Request for verification can be submitted only online from website of CBSE along with fee of Rs.500/- per subject as per schedule given in Annexure-I. b)  In case applying from India the requisite fee of Rs.500/- per...
  • Honourable Prime Minister Shri Narendra Modi ji said "It is our responsibility to ensure that the right spirit of yoga is conveyed to everyone." To promote wellbeing and awareness about Yoga amongst students, the Ministry of Human Resource Development (MHRD) through National Council of Educational Research and Training (NCERT) is taking multi-dimensional initiative to promote Yoga in curriculum...
  • For awarding the grades, the Board shall put all the passed students in a rank order and will award grades as follows: · A-1 Top 1/8th of the passed candidates· A-2 Next 1/8th of the passed candidates· B-1 Next 1/8th of the passed candidates· B-2 Next 1/8th of the passed candidates· C-1 Next 1/8th of the passed candidates· C-2 Next 1/8th of the passed candidates· D-1 Next 1/8th of the passed...
  • The process for starting the registration for compartment examinations for class 10 and class 12 has started. CBSE has recently issued a notification providing details of the schedule to be followed for registration and submission of fees. The CBSE board has also sent the notification to the schools regarding compartment examinations process for regular and private students. CBSE will activate...