Question Set B

cbse 12th Standard Chemistry Aldehydes , Ketones and Carboxylic Acids Important Questions And Answers Study Material - QB365

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Questions:

Multiple Choice Question

45 x 1 = 45

Which is the most suitable reagent for the following conversion?

(a)

Tollen's reagen

(b)

Benzoyl peroxide

(c)

I₂ and NaOH solution

(d)

Sn and NaOH solution

Compounds A and C in the following reaction are

(a)

identical

(b)

positional isomers

(c)

functional isomers

(d)

optical isomers

The reaction of P:Toluidine with CHCl₃ and KOH gives

(a)

(b)

(c)

(d)

(a)

(b)

(c)

(d)

\(\mathrm{CH}_{3} \mathrm{COOH} \stackrel{\mathrm{SOCl}_{2}}{\longrightarrow} \ ^{\prime} \mathrm{A}^{\prime} \frac{\text { Benzene }}{\mathrm{Anhy} \mathrm{AlCl}_{3}}> ^{\prime} \mathrm{B}^{\prime} \stackrel{\mathrm{HCN}}{\longrightarrow} \ ^{\prime} \mathrm{C} ^{\prime} \stackrel{\mathrm{HOH}}{\longrightarrow} \ ^{\prime} \mathrm{D} ^{\prime}\)
The product 'D' is:

(a)

(b)

(c)

(d)

Which of the following compounds will react with sodium hydroxide solution in water?

(a)

C₆H₅OH

(b)

C₆H₅CH₂OH

(c)

(CH₃ )₃ COH

(d)

C₂H₅OH

Which of the following species can act as the strongest base?

(a)

OH^-

(b)

C₆H₅O^-

(c)

RO^-

(d)

\(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CONa}+\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Cl} \stackrel{-\mathrm{NaCl}}{\longrightarrow}\left(\mathrm{CH}_{3}\right)_{3} \mathrm{COC}_{2} \mathrm{H}_{5}\) is called

(a)

Etard reaction

(b)

Gattermann Koch reaction

(c)

Williamson synthesis

(d)

Esterification

3-methyl pent-2-ene on reaction with HBr in presence of peroxide forms an addition product. The number of possible stereoisomers for the product are

(a)

(b)

(c)

(d)

10.

The synthesis of alkyl fluoride is best accomplished by

(a)

Finkelstein reaction

(b)

Swartz reaction

(c)

Free radical flilorination

(d)

Sandmeyers reaction

11.

Which of the following products is formed in the given reaction?

(a)

(b)

(c)

(d)

12.

Which of the following is the strongest acid?

(a)

CH₃COOH

(b)

CICH₂COOH

(c)

Cl₂HCOOH

(d)

CI₃C-COOH

13.

Which of the following compounds is most reactive towards nucleophilic addition reactions?

(a)

(b)

(c)

(d)

14.

In the reaction, \(\begin{equation} \mathrm{H}_{3} \mathrm{C} \longrightarrow \mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CN} \end{equation}\)
Identify the product formed in the given reaction.

(a)

\(\mathrm{H}_{3} \mathrm{C}-\mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CN}\)

(b)

\(\mathrm{H}_{3} \mathrm{C}-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CHO}\)

(c)

\(\mathrm{H}_{3} \mathrm{CCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CHO}\)

(d)

None of the above

15.

When freon is manufactured by tetrachloromethane, the reaction involved in this process is called

(a)

Sandmeyer reaction

(b)

Swarts reaction

(c)

Finkelstein reaction

(d)

All of these

16.

Which of the carbon atoms present in the molecule given below are asymmetric?

(a)

1, 2, 3, 4

(b)

2, 3

(c)

1,4

(d)

1, 2, 3

17.

Which of the following compounds will give racemic mixture on nucleophilic substitution by OH^- ion?

(a)

(i)

(b)

(i), (ii) and (iii)

(c)

(ii) and (iii)

(d)

(i) and (iii)

18.

Arrange the following compounds in the increasing order of their densities.

(a)

(i) < (ii) < (iii) < (iv)

(b)

(i) < (iii) < (iv) < (ii)

(c)

(iv) < (iii) < (ii) < (i)

(d)

(ii) < (iv) < (iii) < (i)

19.

During the preparation of arenediazonium salts, the excess of nitrous acid, if any, is destroyed by adding.

(a)

Aq.NaOH

(b)

Aq.Na₂CO₃

(c)

Aq.NH₂CONH₂

(d)

Aq.KI

20.

What reagent is used in Hinsberge test of amines?

(a)

(CH₃CO)₂O and pyridine

(b)

C₆H₅SO₂CI in aq.NaOH

(c)

NaNO₂ in aq.H₂SO₄

(d)

CH₃I (excess) followed by AgOH

21.

The compound that will react most ready with NaOH to form methanol is

(a)

(CH₃)₄N⁺I^-

(b)

CH₃OCH₃

(c)

(CH₃)₃S⁺I^-

(d)

(CH₃)₃CCI

22.

The gas leaked from storage tank of the Union Carbide plant in Bhopal gas tragedy was

(a)

phosgene

(b)

methylisocyanate

(c)

methylamine

(d)

ammonia

23.

Amongst the following amines, which one has the highest pK_b value in aqueous solution?

(a)

Methanamine

(b)

N, N-Dimethylaniline

(c)

Ethanamine

(d)

Benzenamine

(e)

N, N-Diethylethanamine

24.

In the given set of reactions: \(2-Bromopropane\overset { alc.AgCN }{ \underset { heat }{ \longrightarrow } } X\overset { LiAIH_{ 4 } }{ \longrightarrow } Y\) . The IUPAC name of the product Y is

(a)

N-isopropylmethanamine

(b)

N-methylpropan-2-amine

(c)

N-methylpropanamine

(d)

butan-2-amine

25.

Number of structural isomers possible from the molecular formula C₃H₉N is

(a)

(b)

(c)

(d)

26.

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)

LiAIH₄ in ether

(c)

Fe and HCI

(d)

Sn and HCI

27.

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

(a)

CH₃NH₂

(b)

NCCH₂NH₂

(c)

(CH₃)₂NH

(d)

C₆H₅NHCH₃

28.

Amoung the following compounds. most acidic is

(a)

p-nitrophenol

(b)

p-hydroxybenzoic acid

(c)

o-hydroxybenzoic acid

(d)

p-toluic acid

29.

What are products of the following reaction? C₆H₅OH + BrCH₂CH₂Br \(\overset{excess HBr}\longrightarrow\)?

(a)

C₆H₅OCH + BrCH₂CH₂Br

(b)

C₆H₅OH + HOCH₂CH₂OH

(c)

C₆H₅Br + HOCH₂CH₂OH

(d)

OCH + BrCH₂CH₂OH

30.

Oxidation of acetaldehyde with selenium dioxide produces

(a)

ethanoic acid

(b)

methanoic acid

(c)

glyoxal

(d)

oxalic acid

31.

Benxaldehyde and acetone can be best distinguished using

(a)

Fehling's solution

(b)

sodium hydroxide solution

(c)

2, 4-DNP

(d)

Tollens' reagent

32.

Ortho-nitrophenol is less soluble in water than p-and m-nitrophenols because

(a)

o-nitrophenol shows intramolecular H-bonding

(b)

o-nitrophenol shows intramolecular H-bonding

(c)

melting point of o-nitrophenols is lower than those of m- and p-nitrophenol

(d)

o-nitrophenol is more volatile in steam than those of m- and p-isomers

33.

When ethylamine is treated with CH₃MgBr, the product is:

(a)

CH₃CH₃

(b)

CH₄

(c)

CH₃CH₂CH₃

(d)

CH₃CH₂CH₂CH₃

34.

The most suitable reagent for the conversion of R-CH₂OH \(\longrightarrow\) R-CHO is

(a)

PCC(Pyridinium chlorochromate)

(b)

KMnO₄

(c)

CrO₃

(d)

K₂Cr₂O₇

35.

During dehydration of alcohols to alkenes by heating with Conc.H₂SO₄, the initial step is

(a)

formation of an ester

(b)

protonation of alcohol molecule

(c)

formation of carbocation

(d)

elimination of water

36.

Choose the incorrect statement

(a)

Primary amines show intermolecular hydrogen bonds.

(b)

tert-Butylamine is a primary amine.

(c)

Tertiary amines do not show intermolecular hydrogen bonds.

(d)

Isopropylamine is a secondary amine.

(e)

Amineshave lower boiling points as compared to those of alcohols of comparable molecular mass.

37.

Nitration of nitrobonzene results in..............

(a)

o-dinitrobenzene

(b)

1, 3, 5-trinitrobenzene

(c)

p-dinitrobenzene

(d)

m-dinitrobenzene

38.

The order of reactivity of the alkenes,(CH₃)₂C = CH₂,CH₃CH = CH₂,CH₂= CH₂

(a)

I > II > III

(b)

I > III > II

(c)

III > II > I

(d)

II > I > III

39.

Consider the following reaction, ethanol \(\overset{PCl_5}\longrightarrow\) X \(\overset{alc.KOH}\longrightarrow\) Y \(\overset{H_2SO_4}{\underset {(ii)H_2O,room temperature}{\longrightarrow}}\) Z The product Z is:

(a)

CH₃CH₂- O - CH₂CH₃

(b)

CH₃CH₂- O-SO₃H

(c)

CH₃CH₂OH

(d)

CH₂= CH₂

40.

With which of the following reagents, carbonyl compound shows addition cum elimination reaction?

(a)

PCl₅

(b)

Brady's reagent

(c)

HCN

(d)

all of these

41.

(CH₃)₃CMgBr on reaction with D₂O produces

(a)

(CH₃)₃CD

(b)

(CH₃)₃COD

(c)

(CD₃)₃CD

(d)

(CD₃)₃OD

42.

Which is the correct increasing order of boiling points of the following compounds?
1-Iodobutane, 1-Bromobutane,
1-Chlorobutane, Butane

(a)

Butane < 1-Chlorobutane < 1-Bromobutane < 1-IOdobutane

(b)

1-Iodobutane < 1-Bromobutane < 1-Chlorobuane < Butane

(c)

Butane < 1-Iodobutane < 1-Bromobutane < 1-Chlorobutane

(d)

Butane < 1-Chlorobutane < 1-Iodobutane < 1-Bromobutane

43.

Which of the following reactions is an example of nucleophilic substitution reaction ?

(a)

2 RX + Na \(\longrightarrow\) R^__R + 2 NaX

(b)

RX + H₂ \(\longrightarrow\) RH + HX

(c)

RX + Mg \(\longrightarrow\) RMgX

(d)

RX + KOH \(\longrightarrow\) ROH + KX

44.

Which of the following sequence of reactions (reagents) can be used for conversion of C₆H₅CH₂CH3 into C₆H₅CH = CH₂ ?

(a)

SOCI₂ ; H₂O

(b)

SO₂CI₂ ; alc. KOH

(c)

CI₂/hv ; H₂O

(d)

SOCI₂ ; alc. KOH

45.

An ether is more volatile than alcohol having the same molecular formula. This is due to

(a)

intermolecular hydrogen bonding in alcohols

(b)

dipolar character of ethers

(c)

alcohols having resonance structures

(d)

intermolecular hydrigen bonding in ethers.

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Answers Key:

Multiple Choice Question

45 x 1 = 45

(b)
positional isomers

(a)
C₆H₅OH

(d)
4

10.

(b)
Swartz reaction

11.

12.

(d)
CI₃C-COOH

13.

14.

(b)
\(\mathrm{H}_{3} \mathrm{C}-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CHO}\)

15.

(d)
All of these

16.

(b)
2, 3

17.

(a)
(i)

18.

(a)
(i) < (ii) < (iii) < (iv)

19.

Urea decomposes \({ NH }_{ 2 }{ CONH }_{ 2 }\ +\ 2HONO\longrightarrow 2{ N }_{ 2 }\uparrow +{ CO }_{ 2 }\uparrow +3{ H }_{ 2 }O.\)

20.

(b)
C₆H₅SO₂CI in aq.NaOH

21.

(a)
(CH₃)₄N⁺I^-

22.

Methylisocyanate (MIC).

23.

All aliphatic amines are more basic than benzenamine. Further, due to the presence of two CH₃ groups on N in N, N-dimethylaniline, it is more basic than aniline or benzenamine. Hence, benzenamine is the weakest base base and hence has the highest pK_b value.

24.