Chemistry NCERT Exemplar Solutions Class 12th Chapter Thirteen: Overview, Questions, Preparation

Which of the following is a 3° amine? 

(A) 1-methylcyclohexylamine

(B) Triethylamine 

(C) Tert-butylamine 

(D) N-methylaniline

The correct IUPAC name for CH₂=CH−CH₂−NH−CH₃ is

(A) Allylmethylamine 

(B) 2-amino-4-pentene

(C) 4-aminopent-l-ene

(D) N-méthylprop-2-en-l-amine

Amongst the following, the strongest base in an aqueous medium is.

(A) CH₃NH₂

(B) NCCH₂NH₂

(C) (CH₃)₂NH

(D) C₆H₅NHCH₃

Benzylamine may be alkylated as shown in the following equation:

C₆H₅CH₂NH₂+R−X→C₆H₅CH₂NHR

Which of the following alkyl halides is best suited for this reaction through S_N¹ mechanism?

(A) CH₃Br

(B) C₆H₅Br

(C) C₆H₅CH₂Br

(D) C₂H₅Br

Which of the following reagents would not be a good choice for reducing an aryl nitro compound to an amine?

(A) H₂ (excess) /Pt

(B) LiAlH₄ in ether

(C) Fe and HCl

(D) Sn and HCl

In order to prepare a primary amine from an alkyl halide with simultaneous addition of one CH₂ group in the carbon chain, the reagent used as a source of nitrogen is

(A) Sodium amide, NaNH₂

(B) Sodium azide, NaN₃

(C) Potassium cyanide, KCN

(D) Potassium phthalimide, C₆H₄(CO₂)N−K⁺

The source of nitrogen in Gabriel synthesis of amines is.

(A) Sodium azide, NaN₃

(B) Sodium nitrite, NaNO₂

(C) Potassium cyanide, KCN

(D) Potassium phthalimide, C₆H₄(CO₂)N−^K+

Amongst the given set of reactants, the most appropriate for preparing 2? amine is.

(A) 2?R−Br+NH₃

(B) 2?R−Br+NaCN followed by H₂/Pt

(C) 1?R−N_H2+RCHO followed by H₂/Pt

(D) 1?R−Br+(2 mol)+ potassium phthalimide followed by H₃O+/ heat

The best reagent for converting 2-phenylpro-panamide into-2-phenyl- propanamine is.

(A) Excess H₂

(B) Br₂ in aqueous NaOH

(C) Iodine in the presence of red phosphorus

(D) LiAlH₄ in ether

The best reagent for converting-2-phenylpro-panamide into 1-phenylethanamine is.

(A) Excess H₂/Pt

(B) NaOH/Br₂

(C) NaBH₄/ methanol

(D) LiAlH₄/ ether

The correct increasing order of basic strength for the following compounds is

(A) (II) <( III )<( I )

(B) (III) <(I)<(II)

(C) (III) < (II) < (I)

(D) (II) <(I)<(III)

In the nitration of benzene using a mixture of conc. H₂SO₄ and conc. HNO₃, the species which initiates the reaction is.

(A) NO₂

(B) NO⁺

(C) NO₂⁺

(D) NH₂

Reduction of aromatic nitro compounds using Fe and HCl gives.

(A) Aromatic oxime 

(B) Aromatic hydrocarbon

(C) Aromatic primary amine

(D) Aromatic amide

Acid anhydrides on reaction with primary amines give.

(A) Amide 

(B) Imide

(C) Secondary amine

(D) Imine

The reaction as ArN₂Cl ArCl + N₂ + CuCl is names

(A) Sandmeyer reaction 

(B) Gatterman reaction

(C) Claisen reaction

(D) Carbylamine reaction

Best method for preparing primary amines from alkyl halides without changing the number of carbon atoms in the chain is

(A) Hoffmann bromamide reaction

(B) Gabriel phthalimide reaction 

(C) Sandmeyer reaction 

(D) Reaction with NH₃ 

Which of the following compounds will not undergo azo coupling reaction with benzene diazonium chloride?

(A) Aniline 

(B) Phenol 

(C) Anisole 

(D) Nitrobenzene

The correct decreasing order of basic strength of the following species is

H₂O,NH₃,OH⁻,NH₂⁻

(A) NH₂⁻ >OH^∗>NH₃>H₂O

(B) OH⁻ >NH₂⁻ >H₂O > NH₃

(C) NH₃ >H₂O > NH₂⁻ >OH⁻

(D) H₂O > NH₃ > OH ⁻ > NH₂⁻

Which of the following methods of preparation of amines will not give the same number of carbon atoms in the chain of amines as in the reactant?

(A) Reaction of nitrile with LiAlH₄

(B) Reaction of amide with LiAlH₄ followed by treatment with water.

(C) Heating alkyl halide with potassium salt of phthalimide followed by hydrolysis

(D) Treatment of amide with bromine in aqueous solution of sodium hydroxide.

Which of the following cannot be prepared by Sandmeyer’s reaction?

(A) Chlorobenzene 

(B) Bromobenzene

(C) Iodobenzene 

(D) Fluorobenzene

Reduction of nitrobenzene by which of the following reagents give aniline?

(A) Sn/HCl

(B) Fe/HCl

(C) H2−Pd

(D) Sn/NH₄OH

Which of the following species are involved in the carbylamine test?

(A) R-NC

(B) CHCl₃

(C) COCl₂

(D) NaNO₂+HCl

The reagents that can be used to convert benzenediazonium chloride to benzene are __________.

(i) SnCl₂ /HCl

(ii) CH₃CH₂OH

(iii) H₃ PO₂

(iv) LiAlH₄

Which of the following amines can be prepared by Gabriel synthesis?

(a) Isobutyl amine 

(b) 2-Phenylethylamine

(c) N-Methylbenzylamine 

(d) Aniline

Under which of the following reaction conditions, aniline gives p-nitro derivative as the major product?

(A) Acetyl chloride/pyridine followed by reaction with conc. H₂SO₄+ conc. HNO₃

(B) Acetic anhydride/pyridine followed by conc. H₂SO₄+ conc. HNO₃

(C) Dil. HCl followed by reaction with conc. H₂SO₄+ conc. HNO₃

(D) Reaction with conc. H₂SO₄+ conc. HNO₃

Which of the following reactions belong to electrophilic aromatic substitution?

(A) Bromination of acetanilide

(B) Coupling reaction of aryldiazonium salts

(C) Diazotization of aniline

(D) Acylation of aniline

Under what reaction conditions (acidic/basic), the coupling reaction of aryl diazonium chloride with aniline is carried out?

A compound Z with molecular formula C3H9N reacts with C6H5SO2Cl to give a solid, insoluble in alkali, identify Z.

A primary amine, RNH₂ can be reacted with CH₃−X to get secondary amine, R−NHCH₃ but the only disadvantage is that 3? amine and quaternary ammonium salts are also obtained as side products. Can you suggest a method where RNH₂ forms only 2? amine?

How will you carry out the following conversions?
(i) Toluene –> p-toIuidine
(ii) p-toluidine diazonium chloride –> p-toluic acid

A solution contains 1 g mol each of p-toluene diazonium chloride and p-nitrophenyl diazonium chloride. To this 1 g mol of alkaline solution of phenol is added. Predict the major product. Explain your answer.

In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct answer out of the following choices:

(a) Both Assertion and Reason are wrong.

(B) Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.

(c) Assertion is correct but Reason is wrong.

(d) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.

(e) Assertion is wrong but Reason is correct.

Assertion (A): Acylation of amines gives a monosubstituted product, whereas alkylation of amines gives polysubstituted product.

Reason (R): Acyl group sterically hinders the approach of further acyl groups.

In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct answer out of the following choices:
(a) Both Assertion and Reason are wrong.
(B) Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
(c) Assertion is correct but Reason is wrong.
(d) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(e) Assertion is wrong but Reason is correct.

Assertion (A): Hofmann’s bromamide reaction is given by primary amines. Reason (R): Primary amines are more basic than secondary amines.

In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct answer out of the following choices:
(a) Both Assertion and Reason are wrong.
(B) Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
(c) Assertion is correct but Reason is wrong.
(d) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(e) Assertion is wrong but Reason is correct.

Assertion (A): N-Ethylbenzene sulphonamide is soluble in alkali.

Reason (R): Hydrogen attached to nitrogen in sulphonamide is strongly acidic.

In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct answer out of the following choices:
(a) Both Assertion and Reason are wrong.
(B) Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
(c) Assertion is correct but Reason is wrong.
(d) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(e) Assertion is wrong but Reason is correct.

Assertion (A): N, N-diethylbenzene sulphonamide is insoluble in alkali. 

Reason (R): Sulphonyl group attached to nitrogen atom is strong electron withdrawing group.

In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct answer out of the following choices:
(a) Both Assertion and Reason are wrong.
(B) Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
(c) Assertion is correct but Reason is wrong.
(d) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(e) Assertion is wrong but Reason is correct.

Assertion (A): Only a small amount of HCl is required in the reduction of nitro compounds with iron scrap and HCl in the presence of steam.

Reason (R): FeCl₂ formed gets hydrolysed to release HCl during the reaction.

In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct answer out of the following choices:
(a) Both Assertion and Reason are wrong.
(B) Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
(c) Assertion is correct but Reason is wrong.
(d) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(e) Assertion is wrong but Reason is correct.

Assertion (A): Aromatic 1° amines can be prepared by Gabriel phthalimide synthesis.

Reason (R): Aryl halides undergo nucleophilic substitution with anion formed by phthalimide.

In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct answer out of the following choices:
(a) Both Assertion and Reason are wrong.
(B) Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
(c) Assertion is correct but Reason is wrong.
(d) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(e) Assertion is wrong but Reason is correct.

Assertion (A): Acetanilide is less basic than aniline.

Reason (R): Acetylation of aniline results in decrease of electron density on nitrogen.

Hemoglobin contains 0.34% of iron by mass. The number of Fe atoms in 3.3g of hemoglobin is (Given: Atomic mass of Fe is 56 u, N_A = 6.022 × 10²³ mol^-1.)

Arrange the following in increasing order of heir covalent character.

(A). CaF₂                                         

(B). CaCl₂

(C) CaBr₂

(D) CaI₂

At $30°C,$ the half life for the decomposition of AB₂ is 200s and is independent of the initial concentration of AB₂. The time required for 80% of the AB₂ to decompose is

Given below are two statements : one is labeled as Assertion A  and the other is labeled as Reason R.

Assertion A: Finest gold is red in colour, as the size of the particles increase, it appears purple then blue and finally gold.

Reason R: The  colour of the colloidal solution depends on the wavelength of light scattered by the dispersed particles.

In the light of the above statements, choose the most appropriate answer from the options given below.

Given below are two statements : one is labeled as Assertion A and the other is labeled as Reason R.

Assertion A: LiF is sparingly soluble in wate.

Reason R: The ionic radius of Li⁺ ion is smallest among its group members, hence has least hydration enthalpy.

In the light of the above statements, choose the most appropriate answer from the options given below.

Given below are two statements : one is labeled as Assertion A and the other is labeled as Reason R.

Assertion A: Boric acid is a weak acid.

Reason R: Boric acid is not able to release H⁺ ion on its own. It receives OH^- ion form water and releases H⁺ ion.

In the light of the above statements, choose the most appropriate answer form the option given below.

The correct decreasing order of priority of functional groups in naming an organic compound as per IUPAC system of nomenclature is

Given below are two statements : one is labeled as Assertion A and the other is labeled as Reason R.

Assertion A: Phenolphthalein is pH dependent indicator, remains colourless in acidic solution and gives pink colour in basic medium.

Reason R: Phenolphthalein is a weak acid. It doesn’t dissociate in basic medium.

In the light of the above statements, choose the most appropriate answer from the options given below.

A 10g mixture of hydrogen and helium is contained in a vessel of capacity 0.0125 m³ at 6 bar ansd $27°$ C. The mass of helium in the mixture is__________g. (nearest integer)

Consider an imaginary ion  The nucleus contains ‘a’% more neutrons that the number f electrons in the ion. The value of ‘a’ is____________. [nearest integer]

For the reaction

H₂F₂(g) ® H₂(g) + F₂(g)

$\Delta U=-59.6kJmo{l}^{-1}at27°C$

The enthalpy change for the above reaction is ()__________kJ mol^-1. [nearest integer]

The elevation in boiling point for 1 molal solution of non-volatile solute A is 3K. The depression in freezing point for 2 molal solution of A in the same solvent is 6 K. The ratio of K_b and K_f i.e. K_b/K_f is 1 : X. The value of X is [nearest integer]

20mL of 0.02 M hypo solution is used for the titration of 10mL of copper sulphate solution, in the presence of excess of KI using starch as an indicator. The molarity of Cu²⁺ is found to be__________× 10^-2 M. [nearest integer]

Given: 2Cu²⁺ + 4I^- ® Cu₂I₂ + I₂

 I₂ +   $2S_2{O}_3^{2-}\to 2I^{-}+S_4{O}_6^{2-}$

The number of non-ionisable protons present in the product B obtained from the following reaction is______________.

C₂H₅OH + PCl₃ ® C₂H₅Cl + A

A + PCl₃ ® B

The spin-only magnetic moment value of the compound with strongest oxidizing ability among MnF₄, MnF₃ and MnF₂ is_________B.M [nearest integer]

Total number of isomers (including stereoisomers) obtained on monochlorination of methylcyclohexane is_______________.

A 100 mL solution of CH₃CH₂MgBr on treatment with methanol produces 2.24 mL of a gas at STP. The weight of gas produced is __________ mg. [nearest integer]

How many of the following drugs is/are example(s) of broad spectrum antibiotics?

Ofloxacin, Penicillin G, Terpineol, Salvarsan.

20 mL of 0.02 M K₂Cr₂O₇ solution is used for the titraction of 10 mL of Fe²⁺ solution in the acidic medium. The molarity of Fe²⁺ solution is ___________× 10^-2 M. (Nearest Integer)

2NO + 2H₂ → N₂ + 2H₂O

The above reaction has been studied at 800°C. The related data are given in the table below.

The order to the reaction with respect to NO is_______________.

Amongst the following, the number of oxide(s) which are paramagnetic in nature is Na₂O, KO₂, NO₂, N₂O, ClO₂, NO, SO₂, Cl₂O (Nearest Integer)

The molar heat capacity for an ideal gas at constant pressure is 20.785JK^-1 mol^-1. The change in internal energy is 5000 J upon heating it from 300 K to 500 K. The number of moles of the gas at constant volume is __________. (Nearest Integer)

According to MO theory, number of species / ions from the following having identical bond order is___________.

CN^-, NO⁺, O₂, $O_2^{+},O_2^{2+}$  

At 310 K, the solubility of CaF₂ in water is 2.34 × 10^-3 g/ 100 mL. The solubility product of CaF₂ is ____________× 10^-8 (mol/L)³. (Give molar mass : CaF₂ = 78 gmol^-1)

The conductivity of a solution of complex with formula CoCl₃(NH₃)₄ corresponds to 1 : 1 electrolyte, then the primary valency of central metal ion is__________________.

In the titration of KMnO₄ and oxalic acid in acidic medium, the change in oxidation number of carbon at the end point is____________.

Optical activity of an enantiomeric mixture is + 12.6° and the specific rotation of (+) isomer is +30°. The optical purity is_____________%

In the following reaction

The % yield for reaction I is 60% and that of reaction II is 50%. The overall yield of the complete reaction is___________% [Nearest integer]