Ans Chemist Chap 1
description
Transcript of Ans Chemist Chap 1
CHAPTER 1
ORGANIC CHEMISTRY
PART A (MULTIPLE CHOICE)
1. A 15. C 29. D2. 4-ethyl-2,2-dimethylhexane 16. B 30. A3. B 17. A 31. C4. A 18. B 32. B5. B 19. D 33. A6. C 20. A 34. D7. C 21. B 35. A8. C 22. B 36. D9. A 23. A 37. C10. B 24. D 38. B11. D 25. C 39. B12. C 26. B 40. D13. A 27. A 41. A14. B 28. A
PART B (STRUCTURED QUESTION)
Alkane, Alkene, Alkyne
1. i) butane (C4H10), butene (C4H8), butyne (C4H6) ii) nonane (C9H20), nonene (C9H18), nonyne (C9H16) iii) hexane (C6H14), hexane (C6H12), hexyne (C6H10)
2. i) propane (C3H8), propene (C3H6), propyne (C3H4) ii) pentane (C5H12), pentene (C5H10), pentyne (C5H8) iii) heptane (C7H16), heptane (C7H14), heptyne (C7H12)
3. i) CnH2n ii) CnH2n iii) CnH2n-2 iv) CnH2n-2
4. i) CnH2n ii) CnH2n+2 iii) CnH2n-2 iv) CnH2n-2
5. a) 5-ethyl-2-methylheptane b) 3,3-dimethylbutyne
6 a) 1,1-dichloro-3,3-dimethylbutene b) 5-ethyl-2-methylheptane
7 a)
heptyne
b)
cis-3-octene
c)
Br
1-bromo-3-methylcyclohexene
d)
1-isopropenyl-2-methylcyclopropane
8 a)
heptene
b)
6-isopropyl-2,3-dimethylnonane
c)
cyclobutylcyclopentane
d)
1-t-butyl-2-methylcyclopropane
9. Initiation
Cl2 Cl + ClPropagation
CH4 + Cl CH3 +
HCl
CH3 + Cl2 CH3Cl + Cl
Termination
CH3 + Cl CH3Cl
10. Cl Cl Cl + Cl
H HH H
H C C H + Cl H C C + HCl
H HH H
H H H H
H C C + Cl Cl CH C Cl + Cl
H H H H
H H H
+H C C Cl
Cl H C C Cl + HCl
H H H H
H H Cl
H C C Cl + Cl Cl H C C Cl + Cl
H H H H
11. a)
b)
c)
d)
12. a)
b)
c)
d)
13. a)
b)
c)
d)
Ni
1-Hexyne + 2H2 Hexane
1-HexyneNi hv
Hexane +
2Cl2+2H2 o 1,1-dichlorohexane60 C
1-Hexyne +2H2Ni +
Br heat 1-bromohexaneHexane2
Ni
1-Hexyne + H2 1-Hexene
Ni
3-Hexyne + 2H2 Hexane
Ni hv3-Hexyne +2H2 2Cl2 3,3-dichorohexaneHexane +
60oC
3-Hexyne +2HNi
I2 heat 3-iodohexaneHexane+2
Ni
3-Hexyne + H2 3-Hexene
H H H H H H
H C C C C C C H
H H H H H H
H H H H H H
H C C C C C C
H H H H H
H H H H H H
H C C C C C C H
H H H H OH OH
H H H H OH
+ COOHH C C C C C
H H H H O
H H H H H H
e)
H C C C C C C OH
f)
H H H H H
H H H H H
HC
C C C C C Cl
H H H H H
g) H H H H H Cl
H C C C C C C Cl
H H H H H H
H H H H Cl H
h)
H C C C C C C
H H H H Cl
i) H H H H Cl H
H C C C C C C Cl
H H H H Cl Cl
14. a) H H H H H H H
H C C C C C C C H
H H H H H H H
b)
H H H H H H
H C C C C C C C H
H H H H H H
c)H H H H OH H H
H CC
C C C C C H
H H H OH H H Hd)
H H H OH O H H
H C C C C + C C C H
H H H O OH H H
e)
f)
g)
h)
i)
15. a.
H H H H OHH H
H C C C C C C C H
H H H H H H H
H H H H Cl H H
H C C C C C C C H
H H H H H
H H H H Cl H H
H C C C C C C C H
H H H H Cl H H
H H H Cl H H
H C C C C C C C H
H H H Cl H H
H H H Cl Cl H H
H C C C C C C C H
H H H Cl Cl H H
Name of reaction : Addition reaction
b. CH3CH2CH2CH(OH)CH3
16. a. KOH/ethanol
b. Step 1: Mg/ether
Step 2: H2O/H+
17. H H H CH3 H H H H CH3 H
H + H+H C C C C C H C C C C C H
H H H H H H H
+ Br -
H H H CH3 H
H C C C C C H
H H H Br H
18.H H H CH3 H H H H CH3 H
C H +Br-Br
H C C C C H C C C C C H
BrH H H H H H
+ Br-
H H H CH3 H
H C C C C C H
H H Br Br H
19.
Alcohols
20 a) ethanol
b) 2-methyl-2-propanol
c) 2-ethyl-1-butanol
21 a) 2-propyl-1-hexanol
b) 2,2-dimethyl-1-propanol
c) methanol
OH22 a)
b)
OH
c)
OH
Cl
23 a) OH
b) Br OH
c)OH
24 CH3CH2OH + K CH3CH2OK + ½ H2
Potassium ethoxide
25 CH3CH2CHOHCH3Excess H2SO4 CH3CH=CHCH3 + CH3CH2CH=CH2 + H2O∆
(major) (minor)
Rule: Saytzeff’s rule
26 a) CH3CH2CH2COOH
b) no product formed
27 a) CH3CH2CH2CH2OHKMnO4/
CH3CH2CH2CHO KMnO4/ CH3CH2CH2COOH+
H+/H /
b) CH3CH=CH2 HBr CH3CHBrCH3 OH-CH3CHOHCH3
c) CH3CH2OH HBr CH3CH2Br + H2O
d) CH3OH + CH3COOHconc.
CH3COOCH3 + H2OH2SO4
28
1-propanol 2-propanol
a) Oxidation a) Oxidation
1-propanol propanoic acid 2-propanol 2-propanone
b) Iodoform test b) Iodoform test
1-propanol X 2-propanol CHI3
c) Lucas test c) Lucas test
1-propanol X 2-propanol 2-chloropropane
29 Reagent X = concentrated H2SO4
IUPAC name = 1-butene or but-1-ene
H H
C C
CH2CH3H
30 (CH3)3COH
31 a)
H H OH H
H C C C C H
H H H H 2-butanol
b)
H H Br H H H
H C C C C C C OH
H H H H H H 4-bromo-1-hexanol
32 a) CH3CH2CH(CH3)CHO or CH3CH2CH(CH3)COOH
2-methyl-2-butanal 2-methylbutanoic acid
b) CH3CH2ONa + H2
Sodium ethoxide hydrogen
33 a) A = 2-methyl-1-propanol
b) B = 2,4-dimethyl-1-butanol or 3,3-dimethyl-2-butanol or 2,3-dimethyl-2-butanol
Alkyl Halide
34
H H Cl H H H H Cl H
H C C C H Cl C C C ClH C C C H
H H Cl H H H H Cl H
1,1-dichloropropane 1,3-dichloropropane 2,2-dichloropropane
H Cl H
H C C C H
Cl H H
1,2-dichloropropane
35 a) 3-bromopentane
b) 1-fluoropropane
c) 2-iodopropane
36 a)
I
b)
Br
c)
Cl
Cl
Cl
37 CH3CH2 H2OH HBr CH3CH2CH2Br + H2O
38 2-iodo-4-methylhexane
39 CH3CH2CHICH3
ethanolic KOHCH3CH=CHCH3 + CH3CH2CH=CH2 + HI
reflux (major) (minor)
Major: 2-butene, Minor: 1-butene
40 CH3CH=CH2 (1-propene)
41 CH3C(CH3)(Cl)CH3 or CH3C(CH3)(Br)CH3 or CH3C(CH3)(I)CH3
ether42 CH3CH2CH2Br + Mg CH3CH2CH2MgBr + H2O
CH3CH2CH3 + OH-Mg-Br
43 CH3CH2CH2Cl + OH - Reflux CH3CH2CH2OH∆
44 1-bromo-1-methylcyclohexane. Because in SN1, the reaction involved the carbocation
formation,therefore the tertiary carbocation is more stable compared to secondary
carbocation. So the 1-bromo-1-methylcyclohexane is more reactive than 1-bromocyclohexane in nucleophilic substitution in SN1.
45
SN1 SN2
RX Nu RX
46.
slow
H I
fast
O +
H H
H
fast
O
H H H
O H
O
47. Because to get the most stable carbocation .
48. HH
HO C I
H
49.H
+ O H
IO
50.H
H Cl Cl Cl
C C C C
H Cl andH
H
51.
Br2-bromo-6-ethyl-5-isopropyl-3-methyl-octane
52. Reagent Y = HBr
Aldehydes & Ketones
53. aldehyde, ketone, aldehyde/ketone, aldehyde, ketone
54. 3-methylbutanal
55. CH2(OH)(C≡N)
56. CH3CH(OH)(C≡N)
57. a)
O
O
b)
OH
O+ 2Ag+ + H2O
O+ 2Ag + 2H+
O
+ 2Ag+ + H2O no reaction
c) propanoic acid
58. a)
O
O
b)
OO
+ 2Ag+ + H2O OH
+ 2Ag + 2H+
O+ 2Ag+ + H2O no reaction
c) butanoic acid
59. a) sodium borohydride
b) HCHO + 2HNaBH4
CH3OH
c) Reduction
60. a) Lithium aluminium hydride
b) CH3CHO + 2H LiAlH4 CH3CH2OHether
61. Ketone: propanone; Reagent: KMnO4/H+, heated
62. CH3(CH2)6CH2OH KMnO4/H+ CH3(CH2)6CHO KMnO4/H+ CH3(CH2)6COOH∆ ∆
Octanoic acid
63. Tollen’s reagent
Tollen’s reagent is a mild oxidizing agent. When butanal is warmed with Tollen’s
reagent, it will be oxidized to butanoic acid while the silver mirror amine complex
[Ag(NH3)2]+ will be reduced to grayish Ag metal forming a silver mirror on the walls of the
test tube.
CH3CH2CH2CHO + 2Ag+ + H2O CH3CH2CH2COOH + 2Ag + 2H+
Butanone will not be oxidized by any oxidizing agent, including Tollen’s reagent.
64. W = 2,3,3-trimethylbutanoic acid
65. a)
O
b) Iodoform test
Reagents: iodine in aqueous sodium hydroxide
Observations: Pale yellow solid with a characteristic smell for compound having
CH3C O
group. No reaction for butanal.
Chemical equation:
CH3CHO + 3 I2 CI3CHO
CI3CHO + OH- CHI3 + HCOO-
66. a) Oxidation test with KMnO4 or K2Cr2O7
O O
KMnO4/H+
Heat OH
Purple colour of KMnO4 decolourised by aldehydes while ketones do
not. OR
Orange dichromate ion (Cr2O7-) is reduced to green colour by aldehydes while
ketones do not.
Tollen’s reagent: silver mirror test
O O
+ 2Ag+ + H2O OH + 2Ag + 2H
+
Colourless Tollen’s reagent is reduced to grey metallic silver by aldehydes while
ketones do not. Silver mirror on the wall of the test tube can be observed.
Fehling’s solution (a solution of cupric salt)
O O
+ 2Cu+ + 5OH
--+ Cu2O + 3H2O
O
Aldehydes reduce the deep blue colour of Fehling’s solution to brick-red (reddish
brown) precipitate of copper(II) oxide, while ketones do not.
b)
H H OH H
H C C C C H
H H H H 2-butanol
Carboxylic Acids
67 a) CH3CH2COOH
b) CH3CH(CH3)CH(OH)COOH
c) CH3(CH2)4COOH
d)
COOH
68 a) CH3COOH
b) CH3C(CH3)(Cl)COOH
c) CH3(CH2)8COOH
d) CH3(CH2)3COOH
69 CH3CH2CH2COOH + CH3OH
Butanoic acid
70 CH3COOCH2CH3 + NaOH
71 a) NaOH
b) CH3COOH
c) CH3CH2COOH
72 a) CH3COOH
b) CH3CH2CH=CHCH2OH
73 a) CH3CH2CH2COOH
b) CH2=CHCH2OH
74 a) ethyl ethanoate
b) methyl propanoate
c) sodium propanoate
conc. H2SO4
CH3CH2CH2COOCH3
refluxCH3COONa + CH3CH2OH
75 a) methyl butanoate
b) magnesium propanoate
c) sodium ethanoate
76 a) Methyl butanoate
conc. H2SO4b) CH3OH + CH3CH2CH2COOH CH3CH2CH2COOCH3 + H2O
Type of reaction: Esterification
77 a)
O
O
b) alcohol, carboxylic acid
Benzene & Aromatic Compounds (Introduction)
78 a)
Cl
b)
C2H5
c)
CH2Cl
d)
Br
F
79. a)
CH2OH
b)
CH2(CH2)5CH3
c)
NH2
d)
F
I
Amines
80. a) CH3NH2
b) CH2C(CH3)(NH2)CH3
c) (C2H5)2NH
d) CH3CH2CH2N(CH2CH3)(CH3)
81. secondary (N-methylethanamine),
tertiary (N,N-dimethylmethanamine),
primary (aniline),
secondary (N-ethylethanamine)
82. The formation of white precipitate after shaking.
83. a) CH3CH2NH2 + CH3CH2CH2Br → CH3CH2HNCH2CH2CH3 + HBr
[H+]b) CH3NH2 + CH3COCH2CH3 → CH3CCH2CH3 + H2O
║NCH3
CH3
│c) CH3N(CH3)2 → CH3NO
│CH3
84. a) CH3CH2CH2CH2NH2 b) CH3CH2CH
║NCH2CH3
+ +
85. CH3NH2 + CH3CHO → CH3CH → CH3CH2 ║ │
NCH3 NHCH3[H][H]