organic chemistry - 2 · 2015-06-25 · organic chemistry dr. sangeeta khanna ph.d 1 chemistry...
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Dr. Sangeeta Khanna Ph.D 1 CHEMISTRY COACHING CIRCLE G:\Obj-Organic Chemistry Test-2.doc
ORGANIC CHEMISTRY - 2
READ INSTRUCTIONS CAREFULLY 1. The test is of 1 hour duration.
2. The maximum marks are 150.
3. This test consists of 50 questions. (Negative Marking)
4. For each question you will be awarded 3 marks if you have darkened only the bubble corresponding
to the correct answer and zero mark if no bubbles are darkened. Minus one (-1) mark will be
awarded for wrong answer
1. The treatment of CH3MgX with CH3 – C C – H produces:
a. CH4 b. CH3 – CH = CH2
c. CH3 – C C – CH3 d. CH3 – CH = CH – CH3
2. Correct order of m.p. is shown in :
a. neo-pentane > n-pentane > iso-pentane b. neo-pentane > iso-pentane > n-pentane c. iso-pentane > neo-pentane > n-pentane d. n-pentane > iso-pentane > neo-pentane
3. A, B and C, respectively are : a. b. c. d. 4. The hydrocarbon which cannot react with sodium in liquid ammonia is:
a. CH3 – CH2 – C C – CH2 – CH3 b. CH3 – CH2 – CH2 – C C – CH2 – CH2 – CH2 – CH3 c. CH3 – CH2 – C C – H d. CH3 – CH = CH – CH3
H3C
C = C H
H
CH3 ;
H3C
C = C H H
CH3
; CH3 CH2 CH2 CH3
H3C C = C
H H
CH3
;
H3C
C = C H
H
CH3 ; CH3 CH2 CH2 CH3
CH3 CH2 CH2 CH3 ;
H3C
C = C H
H
CH3 ;
H3C C = C
H H
CH3
H3C
C = C H
H
CH3 ; CH3 CH2 CH2 CH3 ;
H3C
C = C H H
CH3
CH3 C C CH3
Na/NH3/C2H5OH
H2/Pd –C/
H2/Ni2B
A
B
C
Dr. Sangeeta Khanna Ph.D
Dr. Sangeeta Khanna Ph.D 2 CHEMISTRY COACHING CIRCLE G:\Obj-Organic Chemistry Test-2.doc
5. The reagent(s) for the following conversion is/are:
a. alcoholic KOH b. alcoholic KOH followed by NaNH2 c. aqueous KOH followed by NaNH2 d. Zn/CH3OH
6. Which of the following is not a good method for the conversion of CH3 – CH2 – CHO to CH3 –CH2 – CH3?
a. HI/Red P4 b. Zn – Hg/HCl
c. NH2NH2/KOH/glycol d.
SHCH
Ni/Hby follow ed SHHC
22|
2
7. a. b. c. d.
8. Zn/OH (ii) O )i( 23 A; A is:
a.
COOHCHCH
|
COOHCHCH
22
22
b.
CHOCHCH
|
CHOCHCH
22
22
c.
OHHCCHCH
|OHCHCHCH
222
222
d. all of these
9. C8H12 on ozonolysis followed by hydrolysis in the presence of Zn, produces one mole of each of
HCHO, CH3 – CO – CH3 and OCH – CH2 – CO – CH3. The compound is:
a. b. CH2 = CH – CH2 – C(CH3) = C(CH3)2 c. d. CH2 = C(CH3) – CH2 – C(CH3) = C(CH3)2
10. The number of optically active products obtained from the complete ozonolysis of the given compound
is:
a. 0 b. 1 c. 2 d. 4
Br
Br
? H H
KCOOΘ
KCOOΘ
Electrolysis , The Product is:
CH3 CH3
CH3 CH3
CH3 CH = CH C CH = CH C CH = CH CH3
CH3
H CH3
H
Dr. Sangeeta Khanna Ph.D
Dr. Sangeeta Khanna Ph.D 3 CHEMISTRY COACHING CIRCLE G:\Obj-Organic Chemistry Test-2.doc
11. Among the following compounds which can be dehydrated very easily?
a. 2|
2223 H
OH
CCHCHCHCH b. CH3 – CH2 – CH2 – CHOH – CH3
c. 32
|
|23 CHCH
CH
OH
CCHCH
3
d. CH3 – CH2 – CH2 – CH2 – OH
12. Which of the following will not give ethane?
a. CH3 – CH2 – COONa + NaOH/CaO b. CH3 – CH2 – NH2 + HI/Red P
c. CH3 – CH2 – Mg – Br + CH3 – NH2 d. CH2 = CH2 + H2 K 373Pd/Pt
13. /OHΘ
A (major)
The major product ‘A’ is: a. b. c. d. 14. B.P. of CF4 (144 K) is much lower than that of n-hexane (341 K) although their molar masses are equal
(90 u). Which of the following is the correct explanation?
a. n-Hexane has saw teeth system b. Electronegativity of F-atom is extremely high c. CF4 has polar bonds d. n-Hexane has very high van der Waals’ forces
15. The correct decreasing order of enthalpy of combustion is shown in:
a. n-pentane > n-butane > isobtutane b. iso-butane > n-butane > n-pentane c. n-butane > iso-butane > n-pentane d. n-pentane > iso-butane > n-butane
16. On mixing a certain alkane with chlorine and irradiating it with UV light, it forms two monochloroalkane.
Which are optically inactive. This alkane would be:
a. neo-pentane b. propane c. pentane d. iso-pentane
17. Which branched chain isomer of the hydrocarbon with molecular mass 72 u gives only one isomer of monochloro substituted alkyl halide?
a. Tertiary butyl chloride b. neo-pentane c. iso-hexane d. neo-hexane
18. The major organic product of the reaction is:
AClCH
CH
CH
CCHK 353333
OHHC/KOH2
|
|3
52
3
3
a. A is 32|
2 CHCH
CH
CCH
3
b. A is 3|
3 CHCH
CH
CCH
3
c. A is CH3 – CH = CH – CH2 – CH3 d. no reaction
N(CH3)3
Dr. Sangeeta Khanna Ph.D
Dr. Sangeeta Khanna Ph.D 4 CHEMISTRY COACHING CIRCLE G:\Obj-Organic Chemistry Test-2.doc
19. The correct order of reactivity of following alkenes for the reaction with H2 gas is:
a. b. c.
d. 20. CH3 – CH = CH2 reacts with HCl/(RCO)2O2.
The main intermediate is:
a. 33 CHHCCH
b. 223 HCCHCH
c. 33 CHHCCH
d. 223 HCCHCH
21. What is the major product of the addition of HCl on ?
a. b. c. d.
22. 3|
|
|3
?2
|
|3 CHH
CH
C
CH
OH
CCHCHCH
CH
CH
CCH
3
33
3
The reagent used is a. BH3 – THF, NaOH – H2O2 b. Hg(CH3COO)2, H2O, NaBH4 c. H2SO4, H2O d. H2O2/FeSO4
23. Which of the following statements is correct?
a. H.B.O. of unsymmetric alkene is always Anti-Markovnikov reaction b. O.M.D.M. of unsymmetric alkene is always Markovnikov reaction c. Reaction of H2O on alkene in the presence of H2SO4 is Markovnikov addition or rearrangement
addition d. All of the above
24. The final product of reaction of but-2-yne with chlorine water is:
a. 32
||
3 CHCCl
O
CCH b. 3
||||
3 CCl
O
C
O
CCH
c. 3||
3 CHCHCl
O
CCH d. all of these
H3C C = C
CH3
H3C CH3 > C = C
H3C CH3
H
>
CH3 H
C = C H3C CH3
H
> CH2 = CH2
H3C C = C
CH3
H3C CH3 < C = C
H3C CH3
H
<
H3C H
C = C H3C CH3
H
< CH2 = CH2
C = C H3C CH3
H
H3C H
C = C H3C CH3
H >
H3C C = C
CH3
H3C CH3 > CH2 = CH2
C = C H3C CH3
H
H3C H
C = C
H3C CH3
H
< H3C
C = C
CH3
H3C CH3 < CH2 = CH2
CH2 – CH2 – Cl CH CH3
Cl
Cl Cl
Dr. Sangeeta Khanna Ph.D
Dr. Sangeeta Khanna Ph.D 5 CHEMISTRY COACHING CIRCLE G:\Obj-Organic Chemistry Test-2.doc
25. Which of the following will give red ppt. on reacting with R – C CH?
a. AgNO3/NH3 b. Cu2Cl2/NH3 c. Na/NH3 d. All of these
26. Which of the following shows electrophilic as well as nucleophilic addition reactions?
a. CH2 = CH2 b. CH CH c. CH3 – CH3 d. CH3 – CH = CH – CH3
27. The correct basic strength of CH3COO–, C6H5O–, OH–, R C C–,
Θ
2HN is:
a. CH3COO– < C6H5O– < OH– < 2
ΘΘ
HNCCR
b. 2356 NHOHCCRCOOCHOHC
c. COOCHOHCOHCCRNH 3562
d. OHNHCCRCOOCHOHC 2356
28. From the following reactions predict the correct order about acid strength.
HC CH + LiNH2 NH3 + HC CLi
NH3 + R–
2NH + RH
a. RH < NH3 < HC CH b. RH > NH3 > CH CH
c. RH > NH3 < HC CH d. RH < NH3 > HC CH 29. In the following reaction:
C7H8 CBAHCl/ZnFe/Br/Cl3 22
the compound ‘C’ is: a. m-bromotoluene b. o-bromotoluene
c. 3-bromo-2, 4, 6-trichlorotoluene d. p-bromotoluene 30. Which will undergo fastest SN2 substitution reaction when treated with NaOH?
a. Br
CH
H
CCH
3|
|25 b. Br
CH
CH
CCH
3
3
|
|3 c. Br
CH
HC
CH
3
52
|
| d. 322
|
|CHCHCH
H
Br
CH
31. Most stable carbocation is:
a. b. c. d. 32. Which one of the following alkylbromides undergoes most rapid solvolysis in methanol solution to give
corresponding methyl ether?
a. b. c. d.
CH3
+
+CH2 CH3
+
CH3
+
C
CH2
Br Br
Br
Br
Dr. Sangeeta Khanna Ph.D
Dr. Sangeeta Khanna Ph.D 6 CHEMISTRY COACHING CIRCLE G:\Obj-Organic Chemistry Test-2.doc
33. In the conversion of ‘X’ is : a. H2/Pt b. Zn – Hg/HCl c. Li/NH3 d. NaBH4 34. The IUPAC names of is:
a. 3-ethyl-4,4-dimethylheptane b. 1, 1-diethyl-2, 2-dimethylpentane c. 4,4-dimethyl-5, 5-dimethylpentane d. 5, 5-diethyl-4, 4-dimethylpentane
35. Which of the following will react most easily with HBr?
a. b.
c. d. 36. Which of the following is correct order w.r.t. acidic character?
a. CH3 – CH2 – CHCl – COOH > CH3 – CHCl – CH2 – COOH > CH2Cl – CH2 – CH2 – COOH b. CH3 – CHCl – CH2 – COOH > CH3 – CH2 – CHCl – COOH > CH2Cl – CH2 – CH2 – COOH c. CH2Cl – CH2 – CH2 – COOH > CH3 – CH2 – CHCl – COOH > CH3 – CHCl – CH2 – COOH d. CH3 – CH2 – CHCl – COOH > CH2Cl – CH2 – CH2 – COOH > CH2 – CHCl – CH2 – COOH
37. The hyperconjuation stabilities of tert-butyl cation and 2-butene, respectively are due to:
a. p (empty) and * electron delocalisations b. * and electron delocalisations c. p (filled) and electron delocalisations d. p (filled) * and - * electron delocalisations
38. Enantiomer of is:
a. b.
CH2 = CH – CH2 – C – CH3
O
X
CH = CH – CH2 – CH
OH
CH3
O2N CH2OH CH2OH
CH3 CH2OH
H
Et
Me
Me
Br
H
HO
Br
H
Et
Br
Br
Me
H
Me
OH
H
Et
Br
Br
Me
H
Me
HO
H3CO CH2OH
Dr. Sangeeta Khanna Ph.D
Dr. Sangeeta Khanna Ph.D 7 CHEMISTRY COACHING CIRCLE G:\Obj-Organic Chemistry Test-2.doc
c. d.
39. What is correct about isomerism for )I(
3
||
223 CH
O
CCHCHCH
)II(
3
||
|3 CH
O
CH
CH
CCH
3
)III(
32
||
23 CHCH
O
CCHCH
a. I and III are position isomers as well as metamers b. II and III are metamers
c. I and II are metamers d. All of the above
40. Which is the correct sequence of stability of the following enols? (Ph = C6H5)
a. 3
|||
3
||||||
OCH
O
CCH
OH
CCHH
O
CCH
OH
CPhPh
O
CCH
OH
CPh
b. Ph
O
CCH
OH
CPhH
O
CCH
OH
CPhCHO
O
CCH
OH
CCH||||||
3
|||
3
c. Ph
O
CCH
OH
CPhOCH
O
CCH
OH
CCHH
O
CCH
OH
CPh|||
3
|||
3
|||
d. 3
|||
3
||||||
CHO
O
CCH
OH
CCHPh
O
CCH
OH
CPhH
O
CCH
OH
CPh
41. The Z-isomer is:
a.
7325 HCCCH
HCH||
b.
I
||
CBr
ClCF
c.
Br
||
C I
ClCH
d.
5237 HC CCH
HCCCH
||523
42. In the Newman projection for 2,2-dimethylbutane, . What are ‘X’ and ‘Y’?
a. H and H b. H and C2H5 c. C2H5 and H d. CH3 and CH3
Et
Me
Br
Br
H
H
OH
Me
Et
Me
Br
Br
H
Me
H
HO
CH3
Y
H H
H3C
X
Dr. Sangeeta Khanna Ph.D
Dr. Sangeeta Khanna Ph.D 8 CHEMISTRY COACHING CIRCLE G:\Obj-Organic Chemistry Test-2.doc
43. Which of the following is correct for the reactions? a. A and B form a racemic mixture
b. C and D form a racemic miture c. A, B, C and D all are the same compound d. A and B are the same compounds while C and D are different compounds
44. Which of the following is not correct for SN1 mechanism?
a. Order of reactivity of halide is CH3 > 1° > 2° > 3° b. Rate [substrate] c. Reaction is favoured by polar solvent
d. Only 50% inversion takes place for an optically active d or compound
45. Which of the following does not show geometrical isomerism?
a. 1, 2-Dichloropent-1-ene b. 1, 3-Dichloropent-1-ene c. 1, 1-Dichloropent-1-ene d. 1, 4-Dichloropent-2-ene
46. Which of the following is strongest nucleophile
a. 3
Θ
HC b. 2
Θ
HN c. HOΘ
d. HCCHΘ
2
47. The nubmer of steroisomers and optically active isomers possible for the compound ,
are respectively:- a. 3, 2 b. 3, 3 c. 4, 4 d. 2, 2
48. Electrolytic Redcution of nitrobenzene is strongly acidic medium will form
a. Aniline b. p-Amino phenol c. nitrosobenzene d. Hydrazobenzene
49. Number of stereocentres and stereisomers of the given compound
a. 1 & 2 b. 2 & 4 c. 3 & 8 d. zero, 2
50. (CH3)2C = CH2 + (CH3)3CH 42SOH?
The main product is:
a. 322|
3 CHCHCHCH
CH
CCH
3
b. 3
|
2|
|
3 CHH
CH
CCH
CH
CH
CCH
3
3
3
c. CH3 – (CH2)6 – CH3 d. no reaction
H3C
C = C
CH3
H H + Br2 A + B
(X)
H3C
C = C CH3
H
H + Br2 C + D
(Y)
Cl
CH3
y
x
C – C
z
x
y
z
Dr. Sangeeta Khanna Ph.D
Dr. Sangeeta Khanna Ph.D 9 CHEMISTRY COACHING CIRCLE G:\Obj-Organic Chemistry Test-2.doc
ORGANIC CHEMISTRY -2 (ANSWERS)
1. A
Sol. CH3 – C C – H + CH3MgX CH4 + CH3 – C C – MgX
2. A
Sol. Branching decreases m.p., but symmetry increases m.p. due to better packing
3. D
4. D
Sol. Na/NH3 cannot reduce C = C double bond. ‘a’ and ‘b’ produce trans-alkenes while ‘c’ works acidically
where H of – C C – H is replaced by Na
5. B
Sol.
6. B
Sol. Zn – Hg/HCl reduction method of carbonyl compounds is called Clemmensen method
7. D
Sol.
At anode Triple bond is not possible in cyclic system 8. B
Sol. Ozonolysis of
CH
HC||
followed by hydrolysis using zinc supplies ‘O’ atoms to double bonded C-atoms
and cleaves this bond. 9. B Sol.
10. A 11. C Sol. It is 3° alcohol that gives 3° carbocation which is easily formed. 12. B Sol. Only CH3 – CH2 – NH2 does not give CH3 – CH3 directly on reacting with HI
Br
Br
KOH (alc.)
H2C = CH – Br
NaNH2 CH = CH
K OCΘ
K OCΘ
O
O
2K+
+
Θ
OC
O
O
Θ
OC
Θ
OC
O
O
Θ
OC
C
C
O
O
O
-2CO2 Two units
C = O, OCH – CH2 – C = O and O = C
H
H CH3
CH3
CH3
can be obtained by the ozonolysis of H2C = CH – CH2 – C = C – CH3
CH3 CH3
Dr. Sangeeta Khanna Ph.D
Dr. Sangeeta Khanna Ph.D 10 CHEMISTRY COACHING CIRCLE G:\Obj-Organic Chemistry Test-2.doc
13. B Sol.
14. D 15. A 16. B 17. B 18. B
Sol.
product) Say tzef f(3
|
332
|
32
|
|3
Cl
KOH/.Alc3
|
|3 CHCH
CH
CCHCHCH
CH
CCHHC
CH
CH
CCHClCH
CH
CH
CCH
333
3
3
3
19. B 20. C Sol. Peroxide effect is for addition of HBr on unsymmetric alkene
ClCHHCCHHClCHCHCH 3333
21. C Sol. 22. C 23. D 24. A 25. B 26. B
Sol. C C bond undergoes electrophilic as well as nucleophilic addition reaction 27. A
Sol. Acid strength is CH3COOH > C6H5OH > HOH > R – C CH > NH3. So, basis strength order of related
nuelophiles is CH3COO– < C6H5O– < OH– < R – C C– < NH
2
28. A
Sol. From 1st equation HC CH is more acidic than NH3 From 2nd equation, NH3 is more acidic than RH (Acid being produced is weaker than the one that produces it)
Acidic strength HC CH > NH3 > RH or RH < NH3 < HC CH 29. A
Sol.
30. D 31. C 32. A 33. D 34. A
Sol.
ptanedimethy lhe-4 ,4Ethy l3
3
1
2
2
|
3|
|
4
2
5
2
6
3
7
HCHCH
CH CH
C
CH
CH
CHCHCHC
3 2
3
3
N(CH3)3 H2C
H
/OH
Θ
+ H2O + N(CH3)3
CH = CH2
H+
CH = CH2
H
CH2 – CH3
3° Cl
– Cl
CH3
3Cl2/
Sunlight
CCl3
Br2/Fe
CCl3
Br
Zn/HCl
Br
CH3
Dr. Sangeeta Khanna Ph.D
Dr. Sangeeta Khanna Ph.D 11 CHEMISTRY COACHING CIRCLE G:\Obj-Organic Chemistry Test-2.doc
35. C
Sol. +I effect of CH3 increases the basic character of OH group and makes its reaction easier with HBr.
36. A Sol. Cl has – I effect and increase acidic character. Moreover, closer is its position COOH group, stronger is
the acid. 37. A
Sol.
3
3
3
3
CH
CH
C
H
CHp)(empty
CH
CH
C
H
CH|
|2
|
|
|
2
38. A Sol.
39. D
40. A 41. B
Sol.
isomerZ
17||
9
5335 I C Br
ClCF
42. B, D
Sol. 52
3
3HCY
32
|
|
2
HX
3
1
CHCH
CH
CH
CHC
3
3
33 CHX
32
3|
|
2
CHY
3 CHHC
CH
CH
CCH
43. A Sol. X is cis and Br2 has anti-attack. The product has to be a racemic mixture Y is trans and anti-attack of Br2 gives meso compound i.e., C and D are same compound 44. A 45. C 46. A 47. A 48. B 49. C 50. B
Sol. 3
|
2
|
|3
CH
CH
CCH|
|3
H2
|3 CH
CH
CCH
CH
CH
CCH
CH
CH
CCHCH
CH
CCH
33
3
3
3|
2
3
33
HCCH
3
|
|2
|
|3
|
|3 3CH
3CH
|
|3
3
3
3
3
3
3
CH
CH
CH
CCH
CH
CH
CCH
CH
CH
CCH
H2C
H
C
H
CH CH3
* H2C
C CH CH3 H
H
H
Et
Me
Me
Br
H
HO
Br
H
Et
Br
Br
Me
H
Me
HO
Et
Me
Br
Br
H
Me
H
HO