CBSE Class 12 Chemistry 2024 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 $The specific sequence in which amino acids are arranged in a protein is called its$
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Q.21 mark $\mathrm{Ar-N_2^+\,X^-} \xrightarrow{\mathrm{Cu\ CN/KCN}} \mathrm{Ar-CN + N_2}$
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Q.31 mark $Out of the following alkenes, the one which will produce tertiary butyl alcohol on acid catalysed hydration is$
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Q.41 mark $Auto-oxidation of chloroform in air and light produces a poisonous gas known as$
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Q.51 mark $Transition metals are known to make interstitial compounds. Formation of interstitial compounds makes the transition metal$
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Q.61 mark $Isotonic solutions have the same$
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Q.71 mark $Which of the following cell was used in Apollo space programme ?$
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Q.81 mark $The rate of a reaction increases sixteen times when the concentration of the reactant increases four times. The order of the reaction is$
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Q.91 mark $In which of the following molecules, C atom marked with asterisk is chiral ?$
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Q.101 mark $Which of the following species can act as the strongest base ?$
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Q.111 mark $Dilution affects both conductivity as well as molar conductivity. Effect of dilution on both is as follows :$
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Q.121 mark $\mathrm{Na_2SO_4 \cdot 10H_2O}$
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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 $Assertion (A) : Zr and Hf are of almost similar atomic radii. Reason (R) : This is due to Lanthanoid contraction.$
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Q.141 mark $Assertion (A) : The units of rate constant of a zero order reaction and rate of reaction are the same. Reason (R) : In zero order reaction, the rate of reaction is independent of the concentration of reactants.$
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Q.151 mark $\mathrm{S_N2}$
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Q.161 mark $+\mathrm{I}$
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Section B

2 marks each

Q.172 marks $State : (a) Kohlrausch law of independent migration of ions. (b) Faraday’s first law of electrolysis.$
Q.182 marks $Classify the following sugars into monosaccharides and disaccharides : Galactose, Glucose, Lactose and Maltose$
Q.19 (a)2 marks $Carry out the following conversions : (i) Nitrobenzene to Aniline (ii) Aniline to Phenol$
OR
Q.19 (b)2 marks $(i) Write a chemical test to distinguish between Dimethyl amine and Ethanamine. (ii) Write the product formed when benzene diazonium chloride is treated with KI.$
Q.202 marks $Show that in case of a first order reaction, the time taken for completion of 99% reaction is twice the time required for 90% completion of the reaction. (log 10 = 1)$
Q.212 marks $0.2\ \mathrm{mol\ L^{-1}}$

Section C

3 marks each

Q.223 marks $\mathrm{[Co(NH_3)_4Cl(NO_2)]Cl}$
Q.233 marks $Give the structure of the major product expected from the following reactions : (a) Reaction of Ethanal with methyl-magnesium bromide followed by hydrolysis. (b) Hydration of But-1-ene in the presence of dilute sulphuric acid. (c) Reaction of phenol with bromine water.$
Q.243 marks $\mathrm{-CHO}$
Q.253 marks $\mathrm{Ni(s) + 2Ag^+(0.01\ M) \longrightarrow Ni^{2+}(0.1\ M) + 2Ag(s)}$
Q.263 marks $\mathrm{S_N1}$
Q.273 marks $\mathrm{K^{-1}mol^{-1}}$
Q.283 marks $\mathrm{C_3H_9N}$

Section D

The oxidation number of the central atom in a complex is defined as the charge it would carry if all the ligands are removed along with the electron pairs that are shared with the central atom. Similarly the charge on the complex is the sum of the charges of the constituent parts i.e. the sum of the charges on the central metal ion and its surrounding ligands. Based on this, the complex is called neutral if the sum of the charges of the constituents is equal to zero. However, for an anion or cationic complex, the sum of the charges of the constituents is equal to the charge on the coordination sphere.
Q.29 (a)1 mark $Define ambidentate ligand with an example.$
Q.29 (b)1 mark $\mathrm{[Co(NH_3)_5Cl]SO_4}$
Q.29 (c)2 marks $Define Chelate effect. How it affects the stability of complex ?$
OR
Q.29 (c) OR2 marks $\mathrm{Na_3[Cr(C_2O_4)_3]}$
Certain organic compounds are required in small amounts in our diet but their deficiency causes specific disease. These compounds are called vitamins. Most of the vitamins cannot be synthesized in our body but plants can synthesize almost all of them. So they are considered as essential food factors. However, the bacteria of the gut can produce some of the vitamins required by us. All the vitamins are generally available in our diet. The term ‘vitamin’ was coined from the words vital + amine, since the earlier identified compounds had amino group. Vitamins are classified into two groups depending upon their solubility in water or fat namely-fat soluble vitamins and water soluble vitamins.
Q.30 (a)1 mark $\mathrm{B_6}$
Q.30 (b)1 mark $Name the vitamin whose deficiency causes increased blood clotting time.$
Q.30 (c)2 marks $Xerophthalmia is caused by the deficiency of which vitamin ? Give two sources of this vitamin.$
OR
Q.30 (c) OR2 marks $Why can’t vitamin C be stored in our body ? Name the disease caused by the deficiency of this vitamin.$

Section E

5 marks each

Q.315 marks $\mathrm{E^{\circ}(Mn^{2+}/Mn)}$
Q.32 (a)5 marks $\mathrm{mol^{-1}}$
OR
Q.32 (b)5 marks $99.68\ ^{\circ}\mathrm{C}$
Q.33 (a)5 marks $\mathrm{C_9H_{10}O}$
OR
Q.33 (b)5 marks $\alpha$

Section A

1 mark each

Q.11 mark $Which of the following species can act as the strongest base ?$
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Q.21 mark $Auto-oxidation of chloroform in air and light produces a poisonous gas known as$
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Q.31 mark $Isotonic solutions have the same$
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Q.41 mark $The specific sequence in which amino acids are arranged in a protein is called its$
Tap an option to check your answer.
Q.51 mark $Transition metals are known to make interstitial compounds. Formation of interstitial compounds makes the transition metal$
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Q.61 mark $\mathrm{Ar-N_2^+\,X^-} \xrightarrow[\mathrm{Cu\ powder}]{\mathrm{HBr}} \mathrm{Ar-Br + N_2}$
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Q.71 mark $\mathrm{CH_3CH = CH_2}$
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Q.81 mark $\mathrm{KCl}$
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Q.91 mark $Dilution affects both molar conductivity as well as conductivity. Effect of dilution on both is$
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Q.101 mark $Which of the following cell is used in inverter ?$
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Q.111 mark $In which of the following molecules, C atom marked with asterisk is chiral ?$
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Q.121 mark $\mathrm{A + 2B \rightarrow C + D}$
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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 $+\mathrm{I}$
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Q.141 mark $\mathrm{S_N2}$
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Q.151 mark $Assertion (A) : The units of rate constant of a zero order reaction and rate of reaction are the same. Reason (R) : In zero order reaction, the rate of reaction is independent of the concentration of reactants.$
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Q.161 mark $Assertion (A) : Zr and Hf are of almost similar atomic radii. Reason (R) : This is due to Lanthanoid contraction.$
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Section B

2 marks each

Q.172 marks $Define the following terms : (a) Faraday’s second law of electrolysis (b) Corrosion$
Q.182 marks $0.2\ \mathrm{mol\ L^{-1}}$
Q.192 marks $Show that in case of a first order reaction, the time taken for completion of 99% reaction is twice the time required for 90% completion of the reaction. (log 10 = 1)$
Q.20 (a)2 marks $Carry out the following conversions : (i) Nitrobenzene to Aniline (ii) Aniline to Phenol$
OR
Q.20 (b)2 marks $(i) Write a chemical test to distinguish between Dimethyl amine and Ethanamine. (ii) Write the product formed when benzene diazonium chloride is treated with KI.$
Q.212 marks $Classify the following sugars into monosaccharides and disaccharides : Fructose, Lactose, Glucose, Maltose$

Section C

3 marks each

Q.223 marks $Give the structure of the major product expected from the following reactions : (a) Reaction of Ethanal with methyl-magnesium bromide followed by hydrolysis. (b) Hydration of But-1-ene in the presence of dilute sulphuric acid. (c) Reaction of phenol with bromine water.$
Q.233 marks $\mathrm{C_3H_9N}$
Q.243 marks $\mathrm{K^{-1}mol^{-1}}$
Q.253 marks $\mathrm{K_3[Fe(CN)_6]}$
Q.263 marks $\mathrm{-CHO}$
Q.273 marks $\mathrm{Ni(s) + 2Ag^+(0.01\ M) \longrightarrow Ni^{2+}(0.1\ M) + 2Ag(s)}$
Q.283 marks $\mathrm{S_N1}$

Section D

Certain organic compounds are required in small amounts in our diet but their deficiency causes specific disease. These compounds are called vitamins. Most of the vitamins cannot be synthesized in our body but plants can synthesize almost all of them. So they are considered as essential food factors. However, the bacteria of the gut can produce some of the vitamins required by us. All the vitamins are generally available in our diet. The term ‘vitamin’ was coined from the words vital + amine, since the earlier identified compounds had amino group. Vitamins are classified into two groups depending upon their solubility in water or fat namely-fat soluble vitamins and water soluble vitamins.
Q.29 (a)1 mark $\mathrm{B_6}$
Q.29 (b)1 mark $Name the vitamin whose deficiency causes increased blood clotting time.$
Q.29 (c)2 marks $Xerophthalmia is caused by the deficiency of which vitamin ? Give two sources of this vitamin.$
OR
Q.29 (c) OR2 marks $Why can’t vitamin C be stored in our body ? Name the disease caused by the deficiency of this vitamin.$
The oxidation number of the central atom in a complex is defined as the charge it would carry if all the ligands are removed along with the electron pairs that are shared with the central atom. Similarly the charge on the complex is the sum of the charges of the constituent parts i.e. the sum of the charges on the central metal ion and its surrounding ligands. Based on this, the complex is called neutral if the sum of the charges of the constituents is equal to zero. However, for an anion or cationic complex, the sum of the charges of the constituents is equal to the charge on the coordination sphere.
Q.30 (a)1 mark $Define ambidentate ligand with an example.$
Q.30 (b)1 mark $\mathrm{[Co(NH_3)_5Cl]SO_4}$
Q.30 (c)2 marks $Define Chelate effect. How it affects the stability of complex ?$
OR
Q.30 (c) OR2 marks $\mathrm{Na_3[Cr(C_2O_4)_3]}$

Section E

5 marks each

Q.31 (a)5 marks $\mathrm{C_9H_{10}O}$
OR
Q.31 (b)5 marks $\alpha$
Q.325 marks $\mathrm{E^{\circ}(Mn^{2+}/Mn)}$
Q.33 (a)5 marks $\mathrm{mol^{-1}}$
OR
Q.33 (b)5 marks $99.68\ ^{\circ}\mathrm{C}$

Section A

1 mark each

Q.11 mark $\mathrm{K_2SO_4}$
Tap an option to check your answer.
Q.21 mark $Dilution affects both conductivity as well as molar conductivity. Effect of dilution on both is as follows :$
Tap an option to check your answer.
Q.31 mark $Which of the following species can act as the strongest base ?$
Tap an option to check your answer.
Q.41 mark $In which of the following molecules, C atom marked with asterisk is chiral ?$
Tap an option to check your answer.
Q.51 mark $The rate of a reaction increases sixteen times when the concentration of the reactant increases four times. The order of the reaction is$
Tap an option to check your answer.
Q.61 mark $Which of the following cell is used in hearing aids ?$
Tap an option to check your answer.
Q.71 mark $Isotonic solutions have the same$
Tap an option to check your answer.
Q.81 mark $Transition metals are known to make interstitial compounds. Formation of interstitial compounds makes the transition metal$
Tap an option to check your answer.
Q.91 mark $Auto-oxidation of chloroform in air and light produces a poisonous gas known as$
Tap an option to check your answer.
Q.101 mark $Out of the following alkenes, the one which will produce tertiary butyl alcohol on acid catalysed hydration is$
Tap an option to check your answer.
Q.111 mark $\mathrm{Ar-N_2^+\,X^-} \xrightarrow{\mathrm{Cu\ CN/KCN}} \mathrm{Ar-CN + N_2}$
Tap an option to check your answer.
Q.121 mark $The specific sequence in which amino acids are arranged in a protein is called its$
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 $Assertion (A) : The units of rate constant of a zero order reaction and rate of reaction are the same. Reason (R) : In zero order reaction, the rate of reaction is independent of the concentration of reactants.$
Tap an option to check your answer.
Q.141 mark $Assertion (A) : Zr and Hf are of almost similar atomic radii. Reason (R) : This is due to Lanthanoid contraction.$
Tap an option to check your answer.
Q.151 mark $Assertion (A) : p-methoxyphenol is a stronger acid than m-methoxy phenol. Reason (R) : Methoxy group exerts +R effect at both ortho and para position.$
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Q.161 mark $\mathrm{S_N2}$
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Section B

2 marks each

Q.17 (a)2 marks $Carry out the following conversions : (i) Nitrobenzene to Aniline (ii) Aniline to Phenol$
OR
Q.17 (b)2 marks $(i) Write a chemical test to distinguish between Dimethyl amine and Ethanamine. (ii) Write the product formed when benzene diazonium chloride is treated with KI.$
Q.182 marks $(\Lambda^{\circ}_{\mathrm{m}})$
Q.192 marks $Classify the following sugars into monosaccharides and disaccharides : Sucrose, Lactose, Glucose, Fructose$
Q.202 marks $0.2\ \mathrm{mol\ L^{-1}}$
Q.212 marks $A first order reaction takes 40 min for 75% decomposition. Calculate rate constant. [Given : log 2 = 0.30, log 4 = 0.60]$

Section C

3 marks each

Q.223 marks $\mathrm{C_3H_9N}$
Q.233 marks $\mathrm{S_N1}$
Q.243 marks $\mathrm{[Co(NH_3)_4Cl(NO_2)]Cl}$
Q.253 marks $\mathrm{-CHO}$
Q.263 marks $\mathrm{Ni(s) + 2Ag^+(0.01\ M) \longrightarrow Ni^{2+}(0.1\ M) + 2Ag(s)}$
Q.273 marks $\mathrm{Br_2}$
Q.283 marks $\mathrm{K^{-1}\ mol^{-1}}$

Section D

The oxidation number of the central atom in a complex is defined as the charge it would carry if all the ligands are removed along with the electron pairs that are shared with the central atom. Similarly the charge on the complex is the sum of the charges of the constituent parts i.e. the sum of the charges on the central metal ion and its surrounding ligands. Based on this, the complex is called neutral if the sum of the charges of the constituents is equal to zero. However, for an anion or cationic complex, the sum of the charges of the constituents is equal to the charge on the coordination sphere.
Q.29 (a)1 mark $\mathrm{[Co(NH_3)_4Cl_2]^+}$
Q.29 (b)1 mark $\mathrm{[Cr(H_2O)_6]Cl_3}$
Q.29 (c)2 marks $\mathrm{d^4}$
OR
Q.29 (c) OR2 marks $\mathrm{[Co(H_2O)(CN)(en)_2]^{2+}}$
Certain organic compounds are required in small amounts in our diet but their deficiency causes specific disease. These compounds are called vitamins. Most of the vitamins cannot be synthesized in our body but plants can synthesize almost all of them. So they are considered as essential food factors. However, the bacteria of the gut can produce some of the vitamins required by us. All the vitamins are generally available in our diet. The term ‘vitamin’ was coined from the words vital + amine, since the earlier identified compounds had amino group. Vitamins are classified into two groups depending upon their solubility in water or fat namely-fat soluble vitamins and water soluble vitamins.
Q.30 (a)1 mark $\mathrm{B_6}$
Q.30 (b)1 mark $Name the vitamin whose deficiency causes increased blood clotting time.$
Q.30 (c)2 marks $Xerophthalmia is caused by the deficiency of which vitamin ? Give two sources of this vitamin.$
OR
Q.30 (c) OR2 marks $Why can’t vitamin C be stored in our body ? Name the disease caused by the deficiency of this vitamin.$

Section E

5 marks each

Q.31 (a)5 marks $\mathrm{mol^{-1}}$
OR
Q.31 (b)5 marks $99.68\ ^{\circ}\mathrm{C}$
Q.32 (a)5 marks $\mathrm{C_9H_{10}O}$
OR
Q.32 (b)5 marks $\alpha$
Q.335 marks $\mathrm{E^{\circ}(Mn^{2+}/Mn)}$