CBSE Class 12 Chemistry 2026 question paper (56/5)

Maximum marks 70 · Time 3 hours · 3 sets

Try each question first, then open its model answer. Where the paper offers a choice, both questions are shown with OR between them.

Section A

1 mark each

Q.11 mark $Which of the reactions is used in the conversion of a ketone into hydrocarbon ?$
Tap an option to check your answer.
Q.21 mark $\mathrm{R-CO-NH_2}$
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Q.31 mark $The major product of carbylamine reaction is :$
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Q.41 mark $Actinoids show larger number of oxidation states :$
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Q.51 mark $\mathrm{CH_3Cl + NaI} \xrightarrow{\text{dry acetone}} \mathrm{A + B}$
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Q.61 mark $The correct formula of Hinsberg’s reagent is :$
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Q.71 mark $\mathrm{(t_{1/2})}$
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Q.81 mark $Which of the following ligands forms a chelate complex ?$
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Q.91 mark $Primary, secondary and tertiary alcohols can be distinguished by :$
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Q.101 mark $\mathrm{C_2H_5NH_2}$
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Q.111 mark $Identify the polysaccharide among the following :$
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Q.121 mark $The polypeptide chain in a protein has amino acids linked with each other in a specific sequence. This specific sequence of amino acids is called :$
Tap an option to check your answer.
For Questions number 13 to 16, two statements are given — one labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer to these questions from the codes (A), (B), (C) and (D) as given below.
Q.131 mark $Assertion (A) : D (+) - Glucose is dextrorotatory in nature. Reason (R) : (+) represents dextrorotatory nature and D represents the configuration.$
Tap an option to check your answer.
Q.141 mark $Assertion (A) : Highest oxidation state of Mn is +7 in first series of transition elements. Reason (R) : Transition metals exhibit variable oxidation states.$
Tap an option to check your answer.
Q.151 mark $Assertion (A) : p-nitrophenol is more acidic than phenol. Reason (R) : Nitro group is an electron-withdrawing group, it stabilises phenoxide ion by dispersal of negative charge.$
Tap an option to check your answer.
Q.161 mark $Assertion (A) : All aliphatic aldehydes give a positive Fehling’s test. Reason (R) : Aliphatic aldehydes are reduced by Fehling’s reagent.$
Tap an option to check your answer.

Section B

2 marks each

Q.17 (A)2 marks $1{\cdot}00$
OR
Q.17 (B)2 marks $\mathrm{CO_2}$
Q.182 marks $(a) Name the cell which was used in the Apollo space programme for providing electrical power. (b) Define limiting molar conductivity.$
Q.192 marks $\mathrm{C_6H_5N_2^{+}Cl^{-} + C_6H_5OH \xrightarrow{OH^{-}}}$
Q.202 marks $(a) What are the products obtained on hydrolysis of sucrose ? (b) What are essential amino acids ?$
Q.212 marks $(a) Write any two fat soluble vitamins. (b) How will you confirm the presence of five - OH groups in a glucose molecule, which are attached to different carbon atoms ?$

Section C

3 marks each

Q.223 marks $\mathrm{Cr\,(s)} \mid \mathrm{Cr^{3+}(aq)}\ (0{\cdot}1\ \mathrm{M}) \parallel \mathrm{Fe^{2+}(aq)}\ (0{\cdot}01\ \mathrm{M}) \mid \mathrm{Fe\,(s)}$
Q.233 marks $\mathrm{A + B \rightarrow C}$
Q.243 marks $\mathrm{(E_a)}$
Q.253 marks $\mathrm{K_3[Cr(C_2O_4)_3]}$
Q.263 marks $\mathrm{CrCl_3 \cdot 6H_2O}$
Q.273 marks $How do you convert the following ? (a) Acetophenone to Benzoic acid (b) Acetonitrile to Acetone (c) Benzoic acid to Benzene$
Q.28 (A)3 marks $\mathrm{CH_3CH(Br)CH_2COOH}$
OR
Q.28 (B)3 marks $\mathrm{C_8H_8O}$

Section D

Ethers are prepared by the dehydration of alcohols in presence of protic acids at 413 K. Symmetrical and unsymmetrical ethers can also be prepared by Williamson synthesis. This reaction involves $\mathrm{S_N2}$ attack of an alkoxide ion on primary alkyl halide. If a tertiary alkyl halide is used, elimination reaction occurs and an alkene is formed, no ether is formed. C – O bond in ethers are cleaved under drastic conditions with excess of HI. When unsymmetrical ethers react with HI, the alkyl halide is formed from smaller alkyl group. If one of the alkyl group is tertiary, the alkyl halide is formed from the tertiary alkyl group because tertiary alkyl carbocation is more stable than the primary carbocation. Cleavage of alkyl aryl ethers takes place at the alkyl-oxygen bond due to more stable aryl-oxygen bond. The order of reactivity of hydrogen halides is HI > HBr > HCl. Aromatic ethers undergo electrophilic substitution reactions. The alkoxy group attached to the aromatic ring activates the ring towards electrophilic substitution and directs the incoming group to ortho- and para-positions.
Q.29 (a)2 marks $\mathrm{(C_6H_5OCH_3)}$
Q.29 (b)1 mark $Write the names of alkyl halide and sodium alkoxide used to prepare tert-butyl ethyl ether.$
OR
Q.29 (b) OR1 mark $\mathrm{CH_3 - I}$
Q.29 (c)1 mark $Why is C - O - C bond angle in ethers slightly greater than tetrahedral angle ?$
Electrochemistry is the study of the relationship between chemical energy and electrical energy. Many spontaneously occurring chemical reactions liberate electrical energy. In electrolysis, electrical energy is converted directly into chemical energy. The product of an electrolytic reaction depends on the nature of the material being electrolysed and the type of electrode used. Oxidising and reducing species present in the electrolytic cell and their standard electrode potential too, affect the products of electrolysis. Electrolysis plays an important role in most people’s daily lives, whether it is for the manufacturing of aluminium, electroplating of metals, or the synthesis of chemical compounds. Michael Faraday was the first scientist who proposed two laws to explain the quantitative aspects of electrolysis, popularly known as Faraday’s laws of electrolysis. Faraday’s laws of electrolysis provide a basis for mathematical analysis of the mass deposited at electrodes and the amount of charge passed through them. Faraday’s laws are fundamental in various applications, including electroplating, metal extraction, battery technology and chemical synthesis. These laws also help in environmental monitoring and in various chemistry experiments.
Q.30 (a)2 marks $\mathrm{CuCl_2}$
Q.30 (b)1 mark $\mathrm{Ag^{+}}$
OR
Q.30 (b) OR1 mark $State Faraday’s second law of electrolysis.$
Q.30 (c)1 mark $\mathrm{Cl^{-}(aq)} \longrightarrow \frac{1}{2}\mathrm{Cl_2(g) + e^{-}}$

Section E

5 marks each

Q.31 (A)5 marks $10{\cdot}5$
OR
Q.31 (B)5 marks $0{\cdot}025$
Q.32 (A)5 marks $\mathrm{Mn^{2+}}$
OR
Q.32 (B)5 marks $\mathrm{E^{o}_{M^{2+}/M}}$
Q.33 (A)5 marks $\mathrm{S_N1}$
OR
Q.33 (B)5 marks $\mathrm{C_4H_9Br}$

Section A

1 mark each

Q.11 mark $\mathrm{R-CO-NH_2}$
Tap an option to check your answer.
Q.21 mark $The correct formula of Hinsberg’s reagent is :$
Tap an option to check your answer.
Q.31 mark $Actinoids show larger number of oxidation states :$
Tap an option to check your answer.
Q.41 mark $\mathrm{CH_3Cl + NaI} \xrightarrow{\text{dry acetone}} \mathrm{A + B}$
Tap an option to check your answer.
Q.51 mark $The major product of carbylamine reaction is :$
Tap an option to check your answer.
Q.61 mark $Which of the reactions is used in the conversion of a ketone into hydrocarbon ?$
Tap an option to check your answer.
Q.71 mark $Which of the following ligands forms a chelate complex ?$
Tap an option to check your answer.
Q.81 mark $\mathrm{(t_{1/2})}$
Tap an option to check your answer.
Q.91 mark $The polypeptide chain in a protein has amino acids linked with each other in a specific sequence. This specific sequence of amino acids is called :$
Tap an option to check your answer.
Q.101 mark $Identify the polysaccharide among the following :$
Tap an option to check your answer.
Q.111 mark $\mathrm{C_2H_5NH_2}$
Tap an option to check your answer.
Q.121 mark $Primary, secondary and tertiary alcohols can be distinguished by :$
Tap an option to check your answer.
For Questions number 13 to 16, two statements are given — one labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer to these questions from the codes (A), (B), (C) and (D) as given below.
Q.131 mark $Assertion (A) : All aliphatic aldehydes give a positive Fehling’s test. Reason (R) : Aliphatic aldehydes are reduced by Fehling’s reagent.$
Tap an option to check your answer.
Q.141 mark $Assertion (A) : D (+) - Glucose is dextrorotatory in nature. Reason (R) : (+) represents dextrorotatory nature and D represents the configuration.$
Tap an option to check your answer.
Q.151 mark $Assertion (A) : Highest oxidation state of Mn is +7 in first series of transition elements. Reason (R) : Transition metals exhibit variable oxidation states.$
Tap an option to check your answer.
Q.161 mark $Assertion (A) : p-nitrophenol is more acidic than phenol. Reason (R) : Nitro group is an electron-withdrawing group, it stabilises phenoxide ion by dispersal of negative charge.$
Tap an option to check your answer.

Section B

2 marks each

Q.172 marks $\mathrm{C_6H_5N_2^{+}Cl^{-} + C_6H_5OH \xrightarrow{OH^{-}}}$
Q.182 marks $(a) Name any two materials other than hydrogen that can be used as fuel in fuel cells. (b) Define molar conductivity.$
Q.19 (a)2 marks $1{\cdot}00$
OR
Q.19 (b)2 marks $\mathrm{CO_2}$
Q.202 marks $(a) Write the hydrolysis products of lactose. (b) What are non-essential amino acids ?$
Q.212 marks $(a) Name two water-soluble vitamins. (b) How will you prove the absence of free - CHO group in the cyclic structure of glucose molecule ?$

Section C

3 marks each

Q.223 marks $\mathrm{Al\,(s)} \mid \mathrm{Al^{3+}(aq)}\ (0{\cdot}1\ \mathrm{M}) \parallel \mathrm{Ni^{2+}(aq)}\ (0{\cdot}01\ \mathrm{M}) \mid \mathrm{Ni\,(s)}$
Q.233 marks $How do you convert the following ? (a) Toluene to Benzaldehyde (b) Benzoyl chloride to Acetophenone (c) Bromobenzene to Benzoic acid$
Q.243 marks $\mathrm{(E_a)}$
Q.253 marks $\mathrm{[Co(NH_3)_4(H_2O)Cl]\,Cl_2}$
Q.263 marks $\mathrm{CrCl_3 \cdot 6H_2O}$
Q.273 marks $\mathrm{A + B \rightarrow C}$
Q.28 (a)3 marks $\mathrm{CH_3CH(Br)CH_2COOH}$
OR
Q.28 (b)3 marks $\mathrm{C_8H_8O}$

Section D

Electrochemistry is the study of the relationship between chemical energy and electrical energy. Many spontaneously occurring chemical reactions liberate electrical energy. In electrolysis, electrical energy is converted directly into chemical energy. The product of an electrolytic reaction depends on the nature of the material being electrolysed and the type of electrode used. Oxidising and reducing species present in the electrolytic cell and their standard electrode potential too, affect the products of electrolysis. Electrolysis plays an important role in most people’s daily lives, whether it is for the manufacturing of aluminium, electroplating of metals, or the synthesis of chemical compounds. Michael Faraday was the first scientist who proposed two laws to explain the quantitative aspects of electrolysis, popularly known as Faraday’s laws of electrolysis. Faraday’s laws of electrolysis provide a basis for mathematical analysis of the mass deposited at electrodes and the amount of charge passed through them. Faraday’s laws are fundamental in various applications, including electroplating, metal extraction, battery technology and chemical synthesis. These laws also help in environmental monitoring and in various chemistry experiments.
Q.29 (a)2 marks $\mathrm{CuCl_2}$
Q.29 (b) (i)1 mark $\mathrm{Ag^{+}}$
OR
Q.29 (b) (ii)1 mark $State Faraday’s second law of electrolysis.$
Q.29 (c)1 mark $\mathrm{Cl^{-}(aq)} \longrightarrow \frac{1}{2}\mathrm{Cl_2(g) + e^{-}}$
Ethers are prepared by the dehydration of alcohols in presence of protic acids at 413 K. Symmetrical and unsymmetrical ethers can also be prepared by Williamson synthesis. This reaction involves $\mathrm{S_N2}$ attack of an alkoxide ion on primary alkyl halide. If a tertiary alkyl halide is used, elimination reaction occurs and an alkene is formed, no ether is formed. C – O bond in ethers are cleaved under drastic conditions with excess of HI. When unsymmetrical ethers react with HI, the alkyl halide is formed from smaller alkyl group. If one of the alkyl group is tertiary, the alkyl halide is formed from the tertiary alkyl group because tertiary alkyl carbocation is more stable than the primary carbocation. Cleavage of alkyl aryl ethers takes place at the alkyl-oxygen bond due to more stable aryl-oxygen bond. The order of reactivity of hydrogen halides is HI > HBr > HCl. Aromatic ethers undergo electrophilic substitution reactions. The alkoxy group attached to the aromatic ring activates the ring towards electrophilic substitution and directs the incoming group to ortho- and para-positions.
Q.30 (a)2 marks $\mathrm{(C_6H_5OCH_3)}$
Q.30 (b) (i)1 mark $Write the names of alkyl halide and sodium alkoxide used to prepare tert-butyl ethyl ether.$
OR
Q.30 (b) (ii)1 mark $\mathrm{CH_3 - I}$
Q.30 (c)1 mark $Why is C - O - C bond angle in ethers slightly greater than tetrahedral angle ?$

Section E

5 marks each

Q.31 (a)5 marks $\mathrm{S_N1}$
OR
Q.31 (b)5 marks $\mathrm{C_4H_9Br}$
Q.32 (a)5 marks $10{\cdot}5$
OR
Q.32 (b)5 marks $0{\cdot}025$
Q.33 (a)5 marks $\mathrm{Mn^{2+}}$
OR
Q.33 (b)5 marks $\mathrm{E^{o}_{M^{2+}/M}}$

Section A

1 mark each

Q.11 mark $The major product of carbylamine reaction is :$
Tap an option to check your answer.
Q.21 mark $\mathrm{CH_3Cl + NaI} \xrightarrow{\text{dry acetone}} \mathrm{A + B}$
Tap an option to check your answer.
Q.31 mark $Which of the reactions is used in the conversion of a ketone into hydrocarbon ?$
Tap an option to check your answer.
Q.41 mark $\mathrm{R-CO-NH_2}$
Tap an option to check your answer.
Q.51 mark $The correct formula of Hinsberg’s reagent is :$
Tap an option to check your answer.
Q.61 mark $Actinoids show larger number of oxidation states :$
Tap an option to check your answer.
Q.71 mark $Primary, secondary and tertiary alcohols can be distinguished by :$
Tap an option to check your answer.
Q.81 mark $\mathrm{C_2H_5NH_2}$
Tap an option to check your answer.
Q.91 mark $Identify the polysaccharide among the following :$
Tap an option to check your answer.
Q.101 mark $The polypeptide chain in a protein has amino acids linked with each other in a specific sequence. This specific sequence of amino acids is called :$
Tap an option to check your answer.
Q.111 mark $\mathrm{(t_{1/2})}$
Tap an option to check your answer.
Q.121 mark $Which of the following ligands forms a chelate complex ?$
Tap an option to check your answer.
For Questions number 13 to 16, two statements are given — one labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer to these questions from the codes (A), (B), (C) and (D) as given below.
Q.131 mark $Assertion (A) : p-nitrophenol is more acidic than phenol. Reason (R) : Nitro group is an electron-withdrawing group, it stabilises phenoxide ion by dispersal of negative charge.$
Tap an option to check your answer.
Q.141 mark $Assertion (A) : All aliphatic aldehydes give a positive Fehling’s test. Reason (R) : Aliphatic aldehydes are reduced by Fehling’s reagent.$
Tap an option to check your answer.
Q.151 mark $Assertion (A) : D (+) - Glucose is dextrorotatory in nature. Reason (R) : (+) represents dextrorotatory nature and D represents the configuration.$
Tap an option to check your answer.
Q.161 mark $Assertion (A) : Highest oxidation state of Mn is +7 in first series of transition elements. Reason (R) : Transition metals exhibit variable oxidation states.$
Tap an option to check your answer.

Section B

2 marks each

Q.172 marks $(a) What are the products obtained on hydrolysis of sucrose ? (b) What are essential amino acids ?$
Q.182 marks $(a) Name the cell used in hearing aids and watches. (b) Define conductivity. Why is direct current (DC) not used for the measurement of resistance of an ionic solution ?$
Q.192 marks $\mathrm{C_6H_5N_2^{+}Cl^{-} + H-C_6H_4-NH_2 \longrightarrow}$
Q.20 (a)2 marks $1{\cdot}00$
OR
Q.20 (b)2 marks $\mathrm{CO_2}$
Q.212 marks $(a) Name the disease caused by the deficiency of Vitamin A. (b) How will you confirm the presence of carbonyl group as an aldehydic group in glucose ?$

Section C

3 marks each

Q.223 marks $\mathrm{Zn\,(s)} \mid \mathrm{Zn^{2+}(aq)}\ (0{\cdot}1\ \mathrm{M}) \parallel \mathrm{Ag^{+}(aq)}\ (0{\cdot}01\ \mathrm{M}) \mid \mathrm{Ag\,(s)}$
Q.233 marks $\mathrm{A + B \rightarrow C}$
Q.243 marks $\mathrm{(E_a)}$
Q.253 marks $\mathrm{K_2[Zn(OH)_4]}$
Q.263 marks $\mathrm{CrCl_3 \cdot 6H_2O}$
Q.273 marks $How do you convert the following ? (a) Benzene to m-Nitroacetophenone (b) Bromobenzene to 1-Phenylethanol (c) But-3-en-2-one to Prop-2-en-1-oic acid$
Q.28 (a)3 marks $\mathrm{CH_3CH(Br)CH_2COOH}$
OR
Q.28 (b)3 marks $\mathrm{C_8H_8O}$

Section D

Ethers are prepared by the dehydration of alcohols in presence of protic acids at 413 K. Symmetrical and unsymmetrical ethers can also be prepared by Williamson synthesis. This reaction involves $\mathrm{S_N2}$ attack of an alkoxide ion on primary alkyl halide. If a tertiary alkyl halide is used, elimination reaction occurs and an alkene is formed, no ether is formed. C – O bond in ethers are cleaved under drastic conditions with excess of HI. When unsymmetrical ethers react with HI, the alkyl halide is formed from smaller alkyl group. If one of the alkyl group is tertiary, the alkyl halide is formed from the tertiary alkyl group because tertiary alkyl carbocation is more stable than the primary carbocation. Cleavage of alkyl aryl ethers takes place at the alkyl-oxygen bond due to more stable aryl-oxygen bond. The order of reactivity of hydrogen halides is HI > HBr > HCl. Aromatic ethers undergo electrophilic substitution reactions. The alkoxy group attached to the aromatic ring activates the ring towards electrophilic substitution and directs the incoming group to ortho- and para-positions.
Q.29 (a)2 marks $\mathrm{(C_6H_5OCH_3)}$
Q.29 (b) (i)1 mark $Write the names of alkyl halide and sodium alkoxide used to prepare tert-butyl ethyl ether.$
OR
Q.29 (b) (ii)1 mark $\mathrm{CH_3 - I}$
Q.29 (c)1 mark $Why is C - O - C bond angle in ethers slightly greater than tetrahedral angle ?$
Electrochemistry is the study of the relationship between chemical energy and electrical energy. Many spontaneously occurring chemical reactions liberate electrical energy. In electrolysis, electrical energy is converted directly into chemical energy. The product of an electrolytic reaction depends on the nature of the material being electrolysed and the type of electrode used. Oxidising and reducing species present in the electrolytic cell and their standard electrode potential too, affect the products of electrolysis. Electrolysis plays an important role in most people’s daily lives, whether it is for the manufacturing of aluminium, electroplating of metals, or the synthesis of chemical compounds. Michael Faraday was the first scientist who proposed two laws to explain the quantitative aspects of electrolysis, popularly known as Faraday’s laws of electrolysis. Faraday’s laws of electrolysis provide a basis for mathematical analysis of the mass deposited at electrodes and the amount of charge passed through them. Faraday’s laws are fundamental in various applications, including electroplating, metal extraction, battery technology and chemical synthesis. These laws also help in environmental monitoring and in various chemistry experiments.
Q.30 (a)2 marks $\mathrm{CuCl_2}$
Q.30 (b) (i)1 mark $\mathrm{Ag^{+}}$
OR
Q.30 (b) (ii)1 mark $State Faraday’s second law of electrolysis.$
Q.30 (c)1 mark $\mathrm{Cl^{-}(aq)} \longrightarrow \frac{1}{2}\mathrm{Cl_2(g) + e^{-}}$

Section E

5 marks each

Q.31 (a)5 marks $\mathrm{Mn^{2+}}$
OR
Q.31 (b)5 marks $\mathrm{E^{o}_{M^{2+}/M}}$
Q.32 (a)5 marks $\mathrm{S_N1}$
OR
Q.32 (b)5 marks $\mathrm{C_4H_9Br}$
Q.33 (a)5 marks $10{\cdot}5$
OR
Q.33 (b)5 marks $0{\cdot}025$