12th Standard CBSE Syllabus & Materials
12th Standard CBSE
CBSE 12th Biology Sexual Reproduction in Flowering Plants Assertion and Reason Study Material - QB365 Set D
NEW12th Standard CBSE
CBSE 12th Biology Sexual Reproduction in Flowering Plants Assertion and Reason Study Material - QB365 Set C
NEW12th Standard CBSE
CBSE 12th Biology Sexual Reproduction in Flowering Plants Assertion and Reason Study Material - QB365 Set B
NEW12th Standard CBSE
CBSE 12th Biology Sexual Reproduction in Flowering Plants Assertion and Reason Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Standard Biology Sexual Reproduction in Flowering Plants Sample Question Papers Study Material - QB365 Set 1
NEW12th Standard CBSE
CBSE 12th Chemistry d- and f- Block Elements Important Questions And Answers Study Material - QB365 Set B
Published on: 25/10/2025
Download CBSE Class 12th Standard CBSE Chemistry question papers, sample papers, important questions, and previous year solved papers in PDF format. Get free study materials, NCERT solutions, and exam preparation resources for Class 12th Standard CBSE Chemistry
Questions + Answers key
Take MCQ Chemistry Test
2 Marks
1.
Why is an alkylamine more basic than ammonia?
2.
Why do amines react as nucleophiles?
3.
Why are aqueous solutions of amines basic in nature?
4.
Give the structure of 'A' in the following reaction.
5.
How can you convert aniline to iodobenzene?
6.
Account for the following:
(i) Diazonium salts of aromatic amines are more stable than those of aliphatic amines.
(ii) Amines are more basic than alcoholes of comparable molecular masses.
7.
How will you bring about the following conversions?
(i) Nitrobenzene to Phenol.
(ii) Aniline to Chlorobenzene.
8.
How will you bring about the following conversions?
(i) Ethanamine to Ethanoic acid
(ii) Aniline to Benzonitrile
9.
How will you bring the following conversions?
(i) Methanamine into Iodomethane
(ii) Chlorobenzene into p-chloroaniline.
10.
Identify A and B in each of the following process:
11.
Complete the following reaction equations:
\((i)\ C_6H_5NH_2+CHCl_3+KOH(alc)\rightarrow\)
(ii) \(C_6H_5N_2Cl+H_3PO_2+H_2O\rightarrow\)
12.
Why cannot aromatic primary amines be prepared by Gabriel phythalimid synthesis?
13.
Arrange the following substances:
C6H5NH2, (C2H5)2NH, (C2H5)3N, C2H5NH2
(i) In an increasing order of basic strength in water
(ii) In a decreasing order of basic strength in gas phase.
14.
How will you distinguish between C6H5CH2NH2 and C6H5NH2? Write the chemical equations for the reactions involved.
15.
Out of ethylamine and ethyl alcohol which has higher boiling boiling point and why?
16.
Amino group is o, p-directing for aromatic electrophilic substitution. Why does aniline on nitroaniline?
17.
Classify the following amines as primary, secondary or tertiary:
(i)
(ii)
(iii) \(\left(\mathrm{C}_{2} \mathrm{H}_{5}\right)_{2} \mathrm{CHNH}_{2}\)
(iv) \(\left[\mathrm{C}_{2} \mathrm{H}_{5}\right)_{2} \mathrm{NH}\)
18.
Write chemical equations for the following conversions:
(i) CH3-CH2-Cl into CH3-CH2-CH2-NH2
(ii) C6H5-CH2-Cl into C6H5-CH2-CH2-NH2
19.
Arrange the following in decreasing order of their basic strength:
C6H5NH2, C2H5NH2, (C2H5)2 NH, NH3
20.
Complete the following acid-base reactions and name the products:
(a) CH3-CH2-CH2-NH2 + HCI \(\rightarrow \)
(b) (C2H5)3N+HCI \(\rightarrow \)
21.
How will you convert 4-nitrotoluene to 2-bromobenzoic acid?
22.
How will you carry out the following conversions?
(i) toluene \(\longrightarrow \) p-toluidine
(ii) p-toluidine diazonium chloride \(\longrightarrow \) p-toluic acid
23.
Write following conversions:
(i) nitrobenzene\(\longrightarrow \)acetanilide
(ii) acetanilide\(\longrightarrow \)p-nitroaniline
24.
How will you bring out the following conversion?
25.
How will you carry out the following conversions?
q.jpg)
q.jpg)
26.
Write structures and IUPAC names of
(i) the amide which gives propanamide by Hoffmann bromamide reaction.
(ii) the amine produced by the Hofmann degradation of benzamide.
27.
Write chemical reaction of aniline with benzoyl chloride and write the name of the product abtained.
28.
Convert
(i) 3-Methylaniline into 3-nitrotoluence
(ii) Aniline into 1, 3, 5-tribromobenzene.
29.
Write the reactions of
(i) aromatic and
(ii) aliphatic primary amines with nitrous acid.
30.
Give plausible explanation for each of the following:
(i) Why are amines less acidic than alcohols of comparable molecular masses?
(ii) Why do primary amines have higher boiling points than tertiary amines?
(iii) Why are aliphatic amines stronger bases than aromatic amines?
2 Marks
1.
It is because alkyl groups are electron releasing in alkyl amines, they will increase electron density on 'N', therefore, they are more basic than NH3.
2.
It is due tp presence of lone pair of electronson nitrogen which they can donate and act as nucleophiles.
3.
\(\mathrm{RNH}_2+\mathrm{H}_2 \mathrm{O} \longrightarrow \stackrel{\oplus}{\mathrm{N}} \mathrm{H}_3+\mathrm{OH}^{-}\). It is due to formation of OH-.
4.
5.
6.
(i) It is because if resonance stabilization in diazonium salts of aromatic amines which is not possible in diazonium salts of aliphatic amines.
(ii) It is because 'N' is less electronegative than O, therefore, lone pair are easily avaiable.
7.
8.
9.
10.
s.jpg)
s.jpg)
11.
(i) \(\underset { Aniline }{ C_{ 6 }H_{ 5 }NH_{ 2 } } +CHCl_{ 3 }+\underset { (alc) }{ 3KOH } \quad { \longrightarrow }\underset { Phenyl\quad carbylamine }{ C_{ 6 }H_{ { 5 } }N_{ \rightarrow }^{ = }C } +3KCl+3H_{ 2 }O\)
(ii) \(\underset { Benzene\\ diazonium\\ Chloride }{ C_{ 6 }H_{ 5 }N_{ 2 }Cl } +\underset { Hypo\\ phosphorus\quad \\ acid }{ H_{ 3 }PO_{ 2 } } +H_{ 2 }O\quad { \longrightarrow }\underset { Benzene }{ C_{ 6 }H_{ 6 } } +\underset { Phosphoric\\ acid }{ H_{ 3 }PO_{ 3 } } +N_{ 2 }+HCl\)
12.
It is because there is double bond character between C\(\rightarrow\)X bond due to which it cannot be broken easily that is why aromatic amines cannot be prepared by Gabriel phthalimide synthesis.
13.
14.
Add CHCI3 and alc. KOH,C6H5 - NH2 gives foul smell of isocyanide whereas C6H5 - NH - CH3 does not.
15.
Ethyl alcohol has higher boiling point than ethlamine because there is stronger intermolecular H- bonding in ethanol than ethylamine due to more electronegativity of oxygen than nitrogen.
16.
It is due to protonation of aniline to form C6H5NH3 which is electron with drawing, hence m-directing.
17.
(i) Primary
(ii) Tertiary
(iii) Primary
(iv) Secondary
18.
19.
The decreasing order of basic strength of the given amines and ammonia follows the following order:
(C2H5)NH > C2H5NH2 > NH3 > C6H5NH2
20.
21.
22.
23.
24.
25.
s.jpg)
(ii) Follow procedures as in (i) till second last step
26.
(i) Propanamine contains three carbons. Hence, the amide molecule must contain four carbon atoms. Structure and IUPAC name of the starting amide with four carbon atoms are given below:
(ii) Benzamide is an aromatic amide containing seven carbon atoms. Hence, the amine formed from benzamide is aromatic primary amine containing six carbon atoms.
27.
28.
29.
(ii) \( { C }_{ 2 }{ H }_{ 5 }{ NH }_{ 2 }+{ \ HNO }_{ 2 } \longrightarrow { C }_{ 2 }{ H }_{ 5 }OH+{ N }_{ 2 }+{ H }_{ 2 }O\\ Ethanamine\quad \quad\quad\quad\quad Nitrus\quad acid\quad \quad \quad \quad Ethanol\)
30.
(i) It is because C2H5O- is more stable than C2H5NH- because oxygen is more electronegative than nitrogen.
(ii) It is because primary amines are associated with intermolecular H-bonding, whereas tertiary arnines are not.
(iii) It is because there is electron withdrawing C6H5- group in aromatic amines which makes them less basic than aliphatic amines in which alkyl group is electron releasing.
12th Standard CBSE Syllabus & Materials
12th Standard CBSE
CBSE 12th Chemistry d- and f- Block Elements Important Questions And Answers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Chemistry Chemical Kinetics Important Questions And Answers Study Material - QB365 Set B
NEW12th Standard CBSE
CBSE 12th Chemistry Chemical Kinetics Important Questions And Answers Study Material - QB365 Set A
NEW12th Standard CBSE
CBSE 12th Chemistry Electrochemistry Important Questions And Answers Study Material - QB365 Set C
NCERT Books
Syllabus
Exam Pattern
Sample Question Papers
Previous year Question Papers
Important Notes
MCQ Practice test
NCERT Exemplers
Case study Questions
Image Based Questions
Passage based Questions
HOT Questions
Value Based Questions
Model Questions Papers
NCERT ( Book Back ) Questions
Assertion and Reason
Important Questions And Answers
CBSE 12th Standard CBSE Subjects
CBSE Standards
