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CAK – 1
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
ALDEHYDES AND KETONES
C1A Physical Properties :
It has high dipole moment
Boiling point are lower than alcohols due to their inability to form intermolecular H-bonding.
B.Pt. are higher than corresponding alkanes due to dipole-dipole interaction.
Carbonyl group can form H-bond with H2O hence they are soluble in water to varying extent.
C1B Method of Preparation :
1. Oxidation :
(a)
(b)
(c)
This oxidation is called as oppenauer oxidation.
2. Rossenmund Reduction :
3. [LiAlH (O-t-C4H
9)
3 or Lithium tri-t-butoxy Aluminium hydride]
4.
5. Hydrolysis of Gem-Dihalide
(a)
(b)
CAK – 2
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
(c) ArCHOArCHClArCHOH
2heat,Cl
322
6. Hydration of Alkynes : Hydration of alkynes gives ketones (except CH CH which gives CH3CHO)
(a) CHOCHCHCH 3HgSO
H,OH
4
2
(b)33
HgSO
H,OH3 COCHCHCHCCH
4
2
7. Hydroboration Oxidation :
Hydroboration of a non-terminal alkyne followed by oxidation of the intermediate yields a ketonebut terminal alkyne yield aldehyde.
8. Use of Grignard Reagent :
(a) With HCN aldehyde is formed.
(b) With RCN a ketone is formed.
9. With Esters
(a)
(b)
10. Decarboxylation of calcium salts of carboxylic acids :
11. Oxo Process :
2 CH3CH = CH
2 + CO + H
2 CH
3CH
2CH
2CHO +
[COH(CO)4] Cobal + Carbonyl hydride
CAK – 3
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
12. Reduction of acid chloride with organocopper compounds :
13. Friedel-Crafts Acylation :
(a)
(b)
14. From Cadmium and Lithium Salts :
1. 2RMgX + CdCl2 R – Cd – R + MgCl
2 + MgX
2
R – Cd – R + R’COCl RCOR’ + RCdCl
R should be 10 alkyl or aryl (–C6H
5)
15. Ozonylysis of Alkene (Zn/H+) Aldehyde/Ketone
C2 Chemical Properties :
1. Nucleophilic Addition to the Carbon-Oxygen Double bond :
The most characteristic reaction of aldehyde and ketone is nucleophilic addition to thecarbon-oxygen double bond.
General Reaction :
Relative reactivity of Aldehydes versus Ketones :
Aldehydes are more reactive than Ketones. There are two reasons for this, they are as follows :
1. Steric Factor 2. Electronic factor
1. Steric Factor : With one group being the small hydrogen atom, the central carbon of the tetrahedralproduct formed from the aldehyde is less crowded and the product is more stable.
With ketones two alkyl groups at the carbonyl carbon causes greater steric crowding in thetetrahedral product and make it less stable. Therefore small concentration is present at equilibrium.
2. Electronic Factor : Because alkyl group are electron releasing therefore aldehydes are more reactiveon electronic grounds as well. Aldehyde have one electron releasing alkyl group to stablise the partialpositive charge on the carbon atom of the carbonyl group. Whereas ketones have two alkyl groups.
CAK – 4
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
(a) Addition of cyanide :
(b) Addition derivatives of ammonia :
(i)
(ii) HCHO reacts with NH3 differently forming UROTROPINE [hexamethylene tetraamine].
6HCHO + 4NH3 (CH
2)
6N
4 + 4H
2O
H2N – G Product
H2N – OH Hydroxylamine = N – OH oxime
H2N – NH
2Hydrazine = N – NH
2Hydrazone
H2N – NHC
6H
5Phenylhydrazine = N – NHC
6H
5Phenylhydrazone
H2N – NHCOCH
2Semicarbazine = NNHCOCH
2Semicarbazone
(c) Addition of Alcohols : Acetal Formation
(i)
CAK – 5
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
(ii)
Important :
(d) Addition of Grignard reagents :
Formaldehyde with Grignard Reagent gives 10alcohol, all higher aldehydes with grignard reagentgive 20 alcohol and ketones with grignard reagent gives the 30 alcohol.
C3 Other Reactions of Aldehyde and Ketones :
(a) Oxidation :
(i) RCHO or ArCHO
Aldehydes (except) benzaldehyde reduce “Fehling’s Solution” (Cu2+ reduced to Cu+) which is analkaline solution of Cu2+ ion complexed with tetrarate ion.
(ii) Example : Tollen’s Test :
OH2NH4Ag2COOCHOH3)NH(Ag2CHOCH 23
mirrorSilver
3–
SolutionColourless
233
Fehling Solution OH2Cu2COOCHOH3Cu2CHOCH 2.PPtdRe
32
3
Tollen’s test is cheifly given by aldehydes. Tollen’s reagent does not attack carbon-carbon doublebond. Aldehyde also reduce benedict’s solution (Cu2+ complexed with citrate ion) to Cu+
(b) (i) Ketones with strong oxidants and at high temperature undergo cleavage of C-Cbond on either side of carbonyl group.
Carbonyl Group after bond cleavage goes with that alkyl group which is of smallersize.
(ii) Ketones are also oxidised from cleavage of bond by caro’s acid (H2SO
5) or
peroxybenzoic acid (C6H
5CO
3H) to esters. RRCOORRCO
]O[
SOH 52 [Bayer’ss
Villiger Oxidation]
CAK – 6
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
(c) Haloform Test :
(i) Methylketones :
(ii) Hypohalite NaOX (NaOH + X2) cannot only halogenate can also oxidise alcohols
(d) Reduction :
(a) Reduction to alcohol
(e) Reduction to hydrocarbons :
(f) Reductive Amination (Discussed under Amines)
(g) Cannizzaro reaction : In the presence of an concentrated base i.e. alkali, aldehydescontaining no -hydrogens undergo self oxidation and reduction to yield a mixture of analcohol.
(i)
(ii)
CAK – 7
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
(h) Crossed Cannizzaro reaction :
(i) Tischenko Reaction :
All aldehyde in presence of aluminium ethoxide, Al(OC2H5)
3 can be simultaneously oxidised
(to acid) and reduced (to alcohols) to form ester. This is called Tischenko reaction and isthus like cannizaro reaction.
(j) Distinction
Aldehyde and Ketones
S.No. Test RCHO RCOR
1. Schiffs magenta no. reactionreagent colour restored by
RCHO
2. Tollen’s reagent is reduced by RCHO is not reduced
3. Fehling’s solution is reduced by RCHO is not reduced(except C
6H
5CHO) -hydroxy, ketones
reudce Tollen’s reagent and Fehling’ssolution
Practice Problems :
1. Identify (Z) in the reaction series, )Y()X(CHCH HydrolysisHBr22 )Z(
NaOH
)excess(I2
(a) C2H
5I (b) C
2H
5OH (c) CHI
3(d) CH
3CHO
2. A compound (X) of the formula C3H
8O yields a compound C
3H
6O on oxidation. To which of the
following class of compounds could (X) belong
(a) aldehyde (b) secondard alcohol
(c) alkene (d) tert. alcohol
3. Which statement is incorrect in the case of acetaldehyde and acetone
(a) both react with hydroxylamine
(b) both react with NaHSO3
CAK – 8
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
(c) both react with hydrazine
(d) both reduce ammonical silver nitrate
4. Which of the following undergoes Cannizzaro’s reaction
(a) CH3CHO (b) CH
3CH
2CHO (c) (CH
3)
2CHCHO (d) HCHO
5. Urotropine is formed by the action of ammonia on
(a) acetaldehyde (b) formaldehyde (c) acetone (d) phenol
6. Hydrocarbons are formed when aldehydes and ketones are reacted with amalgamated zinc andconc. HCl. The reaction is called
(a) Cannizzaro’s reaction (b) Clemmensen’s reduction
(c) Rosenmund’s reaction (d) Tischenko reaction
7. When acetaldehyde is treated with aluminium ethoxide, it forms
(a) ethyl acetate (b) ethyl alcohol
(c) acetic acid (d) methyl propionate
8. Chloretone is formed when chloroform reacts with
(a) formaldehyde (b) acetaldehyde (c) acetone (d) benzaldehyde
9. Which of the following reagent reacts differently with HCHO, CH3CHO and CH
3COCH
3
(a) HCN (b) NH2OH (c) C
6H
5NHNH
2(d) NH
3
10. In the following sequence of reactions, the end product is
()B()A(CaC ]O[SOH/HgOH2
422
2
)E()D()C( heat)OH(Ca 2
(a) acetaldehyde (b) formaldehyde (c) acetic acid (d) acetone
11. In the following sequence of reactions, the end product is
()A(CHHC]OH[
MgXCHSOH/Hg
2
3422
)C()B( ]O[
(a) acetaldehyde (b) isopropyl alcohol
(c) acetone (d) ethyl alcohol
12. In the following sequence of reactions, the end product is )B()A(CHOCH OHHCN3
2
(a) CH3COOH (b) CH
3CHOHCOOH
(c) CH3CH
2NH
2(d) CH
3CONH
2
13. A compound, C5H
10O, forms a phenyl hydrazone and gives negative Tollen’s and iodoform tests. The
compound on reduction gives n-pentane. The compound A is
(a) pentanal (b) pentanone-2 (c) pentanone-3 (d) amyl alcohol
14. The product Z in the series is
YXCHCH HydrolysisHBr22 Z
32
2
CONa
)excess(I
(a) C2H
5I (b) C
2H
5OH (c) CHI
3(d) CH
3CHO
15. If formaldehyde and KOH are treated together, we get
(a) methane (b) methanol (c) ethyl acetate (d) acetylene
16. The correct order of reactivity in nucleophilic addition reaction CH3CHO, CH
3COC
2H
5 and
CH3COCH
3 is
(a) CH3CHO > CH
3COCH
3 > CH
3COC
2H
5
(b) C2H
5COCH
3 > CH
3COCH
3 > CH
3CHO
(c) CH3COCH
3 > CH
3CHO > C
2H
5COCH
3
(d) CH3COCH
3 > C
2H
5COCH
3 > CH
3CHO
CAK – 9
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
17. To distinguish between 2-pentanone and 3-pentanone which reagent can be used
(a) NaOH/I2
(b) Tollen’s reagent
(c) K2Cr
2O
7/H+ (d) Zn–Hg, HCl
18. CH3CH = CHCHO is oxidised to CH
3 – CH = CHCOOH, using oxidising agent as
(a) alkaline KMnO4
(b) K2Cr
2O
7/conc. H
2SO
4
(c) ammonical AgNO3
(d) dilute HNO3
19. m-chloro benzaldehyde on reaction with conc. KOH at room temperature gives
(a) potassium m-chloro benzoate and m-hydroxy benzaldehyde
(b) m-chloro benzyl alcohol and m-hydroxy benzaldehyde
(c) m-chloro benzyl alcohol and m-hydroxy benzyl alcohol
(d) m-chloro benzyl alcohol and potassium m-chloro benzoate
20. The reagent which can be used to distinguish acetophenone from benzophenone is :
(a) 2, 4-dinitrophenyl hydrazine (b) benedict reagent
(c) I2 and Na
2CO
3(d) aqueous solution of NaHSO
3
21. Best starting material to synthesize 2-methyl-2-butenoic acid is
(a) (b) CH3CH
2CH
2CHO
(c) (d)
22. X and Y can be distinguished by :
(a) silver-mirror test(b) iodoform test (c) both (d) none
23. Which of the following will give haloform test
(a)3
||O
3 CClCCH (b) ICHCCH 2
OH|
3
(c) ClCHCCH 2
O||
3 (d) all
[Answers : (1) c (2) b (3) d (4) d (5) b (6) b (7) a (8) c (9) d (10) d (11) c (12) b (13) c (14) c (15) b(16) a (17) a (18) a (19) d (20) c (21) c (22) c (23) d]
CAK – 10
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
SINGLE CORRECT CHOICE TYPE
1. Which of the following reagent reacts differentlywith HCHO, CH
3CHO and CH
3COCH
3
(a) HCN (b) NH2OH
(c) C6H
5NHNH
2(d) NH
3
2. In the following sequence of reactions, the endproduct is
)B()A(CHOCHheat
agentgDehydratin
alkalimild
onCondensati3
(a) aldol
(b) crotonaldehyde
(c) paraldehyde
(d) metaldehyde
3. Which of the following reaction is a condensationreaction
(a) HCHO Paraformaldehyde
(b) CH3CHO Paraldehyde
(c) CH3COCH
3 Mesityl oxide
(d) CH2 = CH
2 Polyethylene
4. A compound A has molecular formula C2Cl
3OH. It
reduces Fehling’s solution and on oxidation gives amonocarboxylic acid. A is obtained by the action ofCl
2 on ethyl alcohol. The compound A is
(a) chloroform
(b) chloral
(c) trichloro ethanol
(d) trichloro acetic acid
5. The product Z in the series is
YXCHCH HydrolysisHBr22
Z32
2
CONa
)excess(I
(a) C2H
5I (b) C
2H
5OH
(c) CHI3
(d) CH3CHO
6. Cyanohydrin of which of the following gives lacticacid on hydrolysis
(a) acetone (b) acetaldehyde
(c) propanal (d) HCHO
7. In the reaction CH3CHO + HCN CH
3CHOHCN,
a chiral centre is produced. The product is
(a) meso compound
(b) laevorotatory
(c) dextrorotatory
(d) racemic mixture
8. Formic acid and formaldehyde can be distinguishedby treating with
(a) Benedict’s solution
(b) Tollen’s reagent
(c) Fehling’s solution
(d) NaHCO3
9. 2CH3CHO 352 )HOC(Al
CH3COOCH
2CH
3. This
reaction is called
(a) Cannizzaro’s reaction
(b) Aldol condensation
(c) Claisen’s reaction
(d) Tischenko reaction
10. The reaction involving condensation of acetic an-hydride with an aromatic aldehyde by a carboxy-late ion is an example of
(a) aldol condensation
(b) benzoin condensation
(c) Perkin reaction
(d) Wurtz reaction
11. Benzaldehyde when refluxed with aqueous alcoholicKCN forms
(a) benzoin
(b) benzene
(c) phenyl cyanide
(d) phenyl isocyanide
12. Benzyl alcohol is obtained from benzaldehyde by
(a) Wurtz reaction
(b) Cannizzaro’s reaction
(c) Perkin reaction
(d) Claisen reaction
13. C6H
6 + CO + HCl 3AlCl.Anhyd
(X) + HCl
The compound (X) is
(a) C6H
5CHO (b) C
6H
5COOH
(c) C6H
5CH
2Cl (d) C
6H
5CH
3
14. Which of the following is the weakest acid
(a) benzene sulphonic acid
(b) benzoic acid
(c) benzyl alcohol
(d) phenol
CAK – 11
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
15. In the Cannizzaro’s reaction given below
22OH PhCOOHCHPhCHOPh2
the slowest step is
(a) attack of OH— at the carbonyl group
(b) the transfer of hydride to the carbonylgroup
(c) the abstraction of proton from thecarboxylic acid
(d) the deprotonation of Ph–CH2OH
16. The reagent(s) which can be used to distinguishacetophenone from benzophenone is (are) :
(a) 2, 4-dinitrophenyl hydrazine
(b) benedict reagent
(c) I2 and Na
2CO
3
(d) aqueous solution of NaHSO3
17. m-chloro benzaldehyde on reaction with conc. KOHat room temperature gives
(a) potassium m-chloro benzoate andm-hydroxy benzaldehyde
(b) m-chloro benzyl alcohol andm-hydroxy benzaldehyde
(c) m-chloro benzyl alcohol and m-hydroxybenzyl alcohol
(d) m-chloro benzyl alcohol and potassiumm-chloro benzoate
18. A natural compound (X), C4H
8O
2, reduces Fehling’s
solution, liberates hydrogen when treated withsodium metal and gives a positive iodoform test.The structure of (X) is
(a) CH3CHOHCH
2CHO
(b) HOCH2CH
2CHO
(c) CH3COCH
2CHO
(d) CH3COCH
2CH
2OH
19.
X and Y can be distinguished by :
(a) silver-mirror test(b) iodoform test
(c) both (d) none
20. Which of the following will give haloform test
(a)3
||O
3 CClCCH
(b) ICHCCH 2
OH|
3
(c) ClCHCCH 2
O||
3
(d) all
21. cannizzaro
X and YY(Y is alcohol, D is deuterium)
X and Y will have structure :
(a)
(b)
(c)
(d) none is correct
22. NaOH
AA
A is :
(a)
(b)
(c)
(d) none is correct
CAK – 12
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
23. A carbonyl compound with molecular weight 86,does not reduce Fehling’s solution but formscrystalline bisulphite derivatives and givesiodoform test. The possible compounds can be
(a) 2-pentanone and 3-pentanone
(b) 2-pentanone and 3-methyl-2-butanone
(c) 2-pentanone and pentanal
(d) 3-pentanone and 3-methyl-2-butanone
24. In the Cannizzaro’s reaction given below,
PhCOOOHPhCHCHOPh2 2OH
the slowest step is
(a) the attack of OH— at the carbonyl group
(b) the transfer of hydride to the carbonylgroup
(c) the abstraction of proton from thecarboxylic acid
(d) the deprotonation of Ph–CH2OH
ANSWERS (SINGLE CORRECTCHOICE TYPE)
1. d
2. b
3. c
4. b
5. c
6. b
7. d
8. d
9. d
10. c
11. a
12. b
13. a
14. c
15. b
16. c
17. d
18. a
19. c
20. d
21. a
22. a
23. b
24. b
CAK – 13
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
EXCERCISE BASED ON NEW PATTERN
COMPREHENSION TYPE
Comprehension-1
)OHC(AolCyclohexan 106acetone
CrOH 42
)HC(C)OHC(B 127heat
HA147
OH)2(
MgICH)1(
3
3
)OHC(E)OHC(D 3127OH)2(
OH,OAg)1(2127
HOAc,Zn)2(
O)1(
3
23
1. The structure of compound B formed is
(a) (b)
(c) (d)
2. The D formed in the above sequence is
(a)
(b)
(c)
(d) HOOC(CH2)
4COOH
3. D on treatment with Ag2O, OH– and upon
acidification forms
(a)
(b)
(c)
(d) HOOC(CH2)
4COOH
Comprehension-2
The following reaction sequence shows how thecarbon chain of an aldehyde may be lengthened bytwo carbon atoms.
heat,HA3126
OH)2(
Zn,EtCOBrCH)1()OHC(KEthanal
3
22
)OHC(M)OHC(LOH)2(
HDIBAL)1(2126
Pt,H2106
2
2
butanal
4. Structure of K formed is
(a)
(b)
(c)
(d)
5. Thus L is
(a)
(b)
(c) CH3CH = CHCO
2Et
(d)
6. Thus M is
(a) CH3CH
2CH
2CO
2Et
(b)
(c)
(d) CH3CH
2COOH
Comprehension-3
A
B
H)ii(
NaOH)i( Product(s) ?
7. The missing reagent A is
(a) OsO4, NaHSO
3(b) dilute KMnO
4
(c) any one of these (d) O3/H
2O
2
8. The missing reagent B is
(a) HIO4
(b) NaIO4
(c) any one of these (d) None
CAK – 14
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
9. The product(s) formed is/are
(a) (b)
(c) both of these (d) none
MULTIPLE CORRECT CHOICE TYPE
1. A new carbon-carbon bond formation is possiblein
(a) Cannizoro reaction
(b) Friedal-craft reaction
(c) Clemensen reduction
(d) Reimen-Tiemann reaction
2. Which of the following undergoes AldolCondensation
(a) Acetaldehyde
(b) propionaldehyde
(c) Benzaldehyde
(d) Trideuteroacetaldehyde
3. Which of the following on reduction with LiAlH4
with give ethyl alcohol ?
(a) (CH3CO)
2O (b) CH
3COCl
(c) CH3CO NH
2(d) CH
3COOC
2H
5
4. Acetophenone is obtained when
(a) Benzoylchloride treated with dimethylcadmium
(b) Acetylchloride is treated with dimethylcadmium
(c) Acetyl chloride is treated with benzenein presence of anhydrous AlCl
3
(d) Benzoyl chloride is reduced with H2 in
presence of Lindar’s catalyst
5. Which of the following on oxidation with alk.KMnO
4 followed by acidification with HCl gives
benzoic acid
(a) Methyl benzene (b) Ethyl benzene
(c) O-xylene (d) p-xylene
6. Which of the following statements aboutBenzaldehyde is/are true ?
(a) Reduces Tollen’s reagent
(b) Undergoes Aldol condensation
(c) Undergoes cannizaro’s reaction
(d) Does not form an addition compoundwith NaHSO
3
7. Base-catalysed Aldol condensation occurs with
(a) propionaldehyde
(b) Benzaldehyde
(c) 2-Methyl propionaldehyde
(d) 2, 2-Dimethyl-propionaldehyde
8. On heating which of the following getdecarboxylated ?
(a) Methylmalonic acid
(b) succinic acid
(c) 2, 2-Dimethyl acetoacetic acid
(d) Maliec acid
9. Cannizaro reaction will be given by
(a) (b)
(c) (d) CCl3 CHO
10. Which of the following is/are correct about anacetal ?
(a) it is a condensation product of twomolecules of aldehyde
(b) it is the condensation product of twomolecules of ketones
(c) it is the condensation product of onemolecular of aldehyde two molecules ofAlcohols
(d) it is a diether
Assertion-Reason Type
Each question contains STATEMENT-1 (Assertion)and STATEMENT-2 (Reason). Each question has4 choices (A), (B), (C) and (D) out of which ONLYONE is correct.
(A) Statement-1 is True, Statement-2 is True;Statement-2 is a correct explanationfor Statement-1
(B) Statement-1 is True, Statement-2 is True;Statement-2 is NOT a correctexplanation for Statement-1
(C) Statement-1 is True, Statement-2 is False
(D) Statement-1 is False, Statement-2 is True
1. STATEMENT-1 : H2CO is a planar molecule.
STATEMENT-2 : In H2CO, C is sp2 hybridised
2. STATEMENT-1 : H2 + PhCH
2CH
2COCl
C/Pd
quinolineorS Ph CH
2CH
2CHO
above reaction is correct.
STATEMENT-2 : The reduction stops at thealdehyde stage because the catalyst is poinsonedby adding quinoline.
CAK – 15
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
3. STATEMENT-1 : 42SOH
The above reaction is pinacol-pinacolonerearrangement.
STATEMENT-2 : In Pinacol-pinacolonerearrangement formation of the cyclopbtyl C+ isunlikely because the ring strain decreases.
4. STATEMENT-1 : When C6H
6 react with
CO + HCl in the presence of CuCl/AlCl3, it form
C6H
5CHO.
STATEMENT-2 : The electrophilic aromaticsubstitution take place in above reaction.
5. STATEMENT-1 : Under wollff-kishner reductionRCHO reduce to CH
4.
STATEMENT-2 : Under Clemmenson reductionpHCH
2CHO reduce to pHCH
2CH
3
6. STATEMENT-1 : H2CO is always oxidised in the
crossed cannizzaro reaction.
STATEMENT-2 : H2CO is the most reactive
aldehyde, it exists in aqueous OH– solution mainlyas the conjugate base of its hydrate, H
2C(OH)O–.
7. STATEMENT-1 : PCC oxidises 10 alcohol toaldehyde and 20 alcohol to ketone.
STATEMENT-2 : Cu dehydrates 30 alcohol toalkene.
8. STATEMENT-1 : Aldehydes are more reactivethan carboxyl group.
STATEMENT-2 : Carbonyl compounds cannotform hydrogen bonding with H
2O.
9. STATEMENT-1 : Boiling points of carbonylcompounds are higher than those of alkanes.
STATEMENT-2 : Boiling points of carbonylcompound are higher because of hydrogen-bonding.
10. STATEMENT-1 : The reaction of aldehydes andketones with LiAlH
4 and NaBH
4 is uncleophilic
addition reaction.
STATEMENT-2 : Aldol condensation reaction isnot given by C
6H
5CHO.
(Answers) EXCERCISE BASED ON NEW PATTERN
COMPREHENSION TYPE
1. a 2. b 3. a 4. c 5. c 6. a
7. c 8. c 9. c
MULTIPLE CORRECT CHOICE TYPE
1. b, d 2. a, b, d 3. a, b, d 4. a, c 5. a, b 6. a, c
7. a, c 8. a, c 9. b, c, d 10. c, d
ASSERTION-REASON TYPE
1. B 2. A 3. C 4. A 5. D 6. A
7. B 8. C 9. C 10. B
CAK – 16
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
INITIAL STEP EXERCISE
(SUBJECTIVE)
1. Complete the following equations and write downthe names of the products :
(i) = O 4
42
LiAlH.2
SOH/KCN.1 ?
(ii) ?CHCCHCHOH,OH)ii(
THF,BD)i(23
22
3
2. Identify the (A), (B), (C) and (D) in the followingreactions sequence :
(i) (CHOCHCHCH NaBH3
4
)C()B()A(H
KCNHCl
ZnCl2
(ii) ()A(BrCHCHCH 2Br.)alc(KOH223
)D()C()B(2
422
Hg
.)dil(SOH
.)alc(KOH
NaNHbyfollowed
(iii) )B()A(CHOCH PClOAg3
52
)D()C(H/OH
MgBrCHH
BaSO/Pd2
32
4
3. What happens when (Give equation only) Chloralis heated with aqueous sodium hydroxide.
4. How will you differentiate between
(i) Acetaldehyde and Acetone.
5. How would you bring the following conversions :
(a) Acetone from acetaldehyde.
(b) Methanal to ethanal (not more than3 steps)
(c) Acetone from methane.
(d) 2-Butanone from ethyl alcohol.
(e) 3-Hexanone from n-propyl alcohol.
6. Arrange the following :
(i) CH3CHO, CH
3COCH
3, HCHO,
C2H
5COCH
3 in decreasing order of
nucleophilic addition.
(ii) CH3COCH
2CHO,CH
3COCH
3,
CH3CHO, CH
3COCH
2COCH
3 in
increasing order of expected enol content.
7. A ketone (A) which undergoes haloform reactiongives compound (B) on reduction. (B) on heatingwith sulphuric acid gives compound (C), whichforms monozonide (D). (D) on hydrolysis inpresence of zinc dust gives only acetaldehyde.Identify (A), (B) and (C). Write down the reactionsinvolved.
8. Show, by equations, how acetaldehyde may beconverted into :
(i) EtOH; (ii) CH3COCl; (iii) CHI
3; (iv) MeCOEt;
(v) CH3CO
2Et; (vi) CH
3CHOHCO
2H; (vii) EtNH
2;
(viii) CH3CHBrCHBrCO
2H.
9. Convert ClCH2CH
2CHO into HOCH
2CHOHCHO.
10. Compound (A) and (B) on reaction in ethermedium and subsequent acidification andoxidation give 2, 5-dimethyl 3-hexanone. What are(A) and(B) ?
11. Identify (A) to (E) as reactant, reagent, product orname of the reaction in following :
(i) )B(OC)CH(3 )A(23
Aldol condensation
(ii) )D(HCOClCH )C(23
Rosenmund’s reaction
(iii) )F(CHCHCH)E( 323
NHNH
ONaHC
22
52
12. Write the structural formula of the main organicprudent formed when : the compound obtained bythe hydration of ethyne is treated with dilutealkali.
13. How can we convert PhCH = CHCOCH3 to
(a) PhCH = CHCOOH
(b) PhCH = CHCHOHCH3
(c) PhCH2CH
2COCH
3
(d) PhCH = CHCH2CH
3
(e) Ph(CH2)
3CH
3
14. An organic compound (A) contains 40% carbonand 6.7% hydrogen. Its V.D. is 15. On reaction witha conc. solution of KOH, it gives two compounds(B) and (C). When (B) is oxidised, the original com-pound (A) is obtained. (C) give effervecence withNaHCO
3. Write the structures of A, B, C and D and
explain the reactions.
15. An organic compound (A), C4H
9Cl on reacting with
aqueous KOH gives (B) and on reaction alc. KOHgives (C) which is also formed on passing thevapours of (B) over heated copper. The compound
CAK – 17
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
(C) readily decolourizes bromine water. Ozonoly-sis of (C) gives two compounds (D) and (E). Com-pound (D) reacts with NH
2OH to give (F) and the
compound (E) reacts with NaOH to give an alcohol(G) and sod. salt (H) of an acid. (D) can also beprepared from propyne on treatment with water inpresence of Hg++ and H
2SO
4. Identify (A) to (H) with
proper reasoning.
16. How would you convert :
17. An organic compound A, C8H
6, on treatment with
dilute H2SO
4 containing HgSO
4 gives a compound
B which can also be obtained from the reaction ofbenzene with an acid chloride in the presence ofanhydrous AlCl
3. The compound B when treated
with iodine and aq. KOH, yields C and a yellowcompound D. Identify A, B, C and D withjustification. Show how C and D is formed.
18. A certain hydrocarbon A was found to contain85.7% C and 14.3 % H. This compound consumes1 molar equivalent of hydrogen to give a saturatedhydrocarbon B. 1.0 g of hydrocarbon A justdecolourised 38.05 of a 5 percent s o l u t i o n(by weight) of Br
2 in CCl
4. Compound A on
oxidation with concentrated KMnO4 gave
compound C (molecular formulae C4H
8O) and
acetic acid. Compound C could easily be preparedby action of acidic aqueous HgSO
4 on 2-Butyne.
Determine the molecular formula of A and deducethe structure of A, B and C
FINAL STEP EXERCISE
(SUBJECTIVE)
1. How would you bring the following conversions :
(a) Ethanal to 2-hydroxy-3-butenoic acid.
(b) Propanal to
2. Convert : (i) n-butanol into 2-ethylhexan-1-ol;(ii) bromocyclohexane into cyclopentancarboxylicacid.
3. Suggest what compounds the letters stand for inthe following equations :
(i)
BCHCHMeCOMeA)ii(
NaNH)i( 2
(ii)
CEtCOClCHPhCOMe 2NaNH22
(iii)
DEtCOClCHBuOHt
BuOKt22
4. Complete the following equations and give reasonsfor your answer.
(i) ?OHCH)OH(CMe H22
(ii) ?MePh)OH(C)OH(PhMeC H
5. Compound (A), C10
H12
O gives off hydrogen ontreatment with sodium metal and also decolourisesBr
2 in CCl
4 to give (B), C
10H
12OBr
2. (A) on treat-
ment with I2 in NaOH gives iodoform and an acid
(C) after acidification. Give structures of (A) to (C)and also of all the geometrical and optical isomersof (A).
6. A organic compound (A), C9H
12O was subjected in
a series of test in the laboratory. It was found thatthis compound
(i) Rotates the plane of polarised light.
(ii) Evolves hydrogen with sodium
(iii) Reacts with NaOH and I2 to produce a
pale yellow solid compound.
(iv) Does not react with Br2/CCl
4.
(v) Reacts with hot KMnO4 to form
compound (B) C7H
6O
2 which can also be
synthesised by the reaction of benzeneand carbonyl chloride followed byhydrolysis.
(vi) looses optical activity as a result offormation of compound (C) on beingheated with HI and P.
(vii) Reacts with Lucas reagent in about 5 min.Give structures of (A) to (C) with properreasoning and draw fischer projectionsfor (A). Give reactions for the stepswherever possible.
CAK – 18
Einstein Classes, Unit No. 102, 103, Vardhman Ring Road Plaza, Vikas Puri Extn., Outer Ring Road
New Delhi – 110 018, Ph. : 9312629035, 8527112111
7. A neutral organic compound (A) on analysis gaveC = 52.17%; H = 13.04%. On mild oxidation (A)gave (B) which on treatment with dilute NaOH gaveanother neutral compound (C) with double themolecular mass. Compound (C) readily loseswater on heating to form (D) which on oxidationgave CH
3CH = CHCOOH (crotonic acid). Identify
(A), (B), (C) and (D) and explain the reactions.
8. (a) Identify A, B, in the following set up
OHO BA 3
(b) An alkyne with 5 carbon atoms permolecule when passed through dilutesulphuric acid containing mercuricsulphate gives a compound which formsan oxime, but has no effect on Fehling’ssolution. The compound on oxidationgives dimethyl acetic acid. It reacts withsodamide to forms a hydrocarbon. Whatis the structure of the alkyne ?
9. When 0.0088 g of compound (A) was dissolved in0.50 g. of camphor, the melting point of camphorwas lowered by 80C. Analysis of (A) gave 68.18% Cand 13.16% H. Compound (A) showed thefollowing reactions : (i) It reacted with acetylchloride and evolved hydrogen with sodium, (ii)When reacted with HCl + ZnCl
2, a dense oily layer
separated out immediately. Compound (A) waspassed over Al
2O
3 at 3500C to give compound (B).
(B) on ozonolysis followed by hydrolysis gave twoneutral compounds (C) and (D) which gavepositive tests with carboyl reagents but only (C)gave a positive test with Fehling solution. Identify(A), (B), (C) and (D) with proper reasoning. K
f for
camphor = 40 mol–1 kg–1.
10. Suggest the appropriate structures for the missingcompound. (The number of carbon atoms remainthe same throughout the reactions)
CBA HOHIOKMnO.dil 44
11.
Identify A to G.
12. Wolff-Kishner reduction of the compound showngave compound A. Treatment of compound A withm-chloroperoxy benzoic acid gave B which onreduction with LiAlH
4 gave C. Oxidation of
compound C with chromic acid gave compound D(C
9H
14O). Identify A, B, C and D.
13. An optically active alkyne A contains 89.52% C and10.48 % H. After hydrogenation over a Pd catalystit is converted to 1-Methyl-4-propyl cyclohexane.When compound A reacts with CH
3MgBr no gas
is liberated. Hydrogenation of A over Lindlarcatalyst, followed by ozonylysis and reaction withKMnO
4 gives product B. Product B reacts with
I2/NaOH and gives a yellow precipitate, which is
filtered off. Acidification of the filterate gives anoptically active product C. Give the structures ofA, B and C and account for all observations.
14. Give the structure for compounds A – F :
CBOHC /HA
OH.2
MgICH.1
acetone
CrOH
A126
3
342
FEDOH.2
OH,OAg
COOHCH/Zn.2
O.1
3
2
3
3
15. C6H
12O
6 can be glucose or fructose. To decide
nature, one can carry out following steps :
?OHC HI/POHHCN6126
3
What can be the end product starting with glucoseand fructose ?
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