10. HALOALKANES AND HALOARENES Objective

10. HALOALKANES AND HALOARENES
1. Good conductor of electricity and heat is
(A) Anthracite coke
(B) Diamond
(C) Graphite
(D) Charcoal
Answer ⇒ (C)
2. In which of the following allotropes of carbon, percentage of carbon is maximum ?
(A) Wood charcoal
(B) Coconut charcoal
(C) Graphite
(D) None of these
Answer ⇒ (C)
3. The hybridisation of carbon in diamond is
(A) sp3
(B) sp2
(c) sp
(D) dsp2
Answer ⇒ (A)
4. Organic compound must contain an element
(A) oxygen
(B) carbon
(C) hydrogen
(D) nitrogen
Answer ⇒ (B)
5. Alkene gives which of the following reactions ?
(A) Addition reaction
(B) Substitution reaction
(C) Both (A) and (B)
(D) None of these
Answer ⇒ (C)
6. Single bond length between carbon-carbon is
(A) 1.34 Å
(B) 1.20 Å
(C) 1.54 Å
(D) none of these
Answer ⇒ (C)
7. Valency of carbon is
(A) 1
(B) 2
(C) 3
(D) 4
Answer ⇒ (D)
8. Criteria for purity of organic solid is
(A) boiling point
(B) melting point
(C) specific gravity
(D) none of these
Answer ⇒ (B)
9. General formula of Alkene is
(A) CnH2n
(B) CnH2n + 2
(C) CnH2n – 2
(D) none of these
Answer ⇒ (A)
10. Hybridisation of carbon in ethane is
(A) sp3
(B) sp2
(C) sp
(D) sp3d2
Answer ⇒ (A)
11. Number of π bonds in ethyne is
(A) 1
(B) 2
(C) 3
(D) 4
Answer ⇒ (B)
12. The compound having general formula CnH2n + 2 is
(A) Alkene
(B) Alkyne
(C) Alkane
(D) none of these
Answer ⇒ (C)
13. The antiseptic action of CHI3 is
(A) due to idoform
(B) due to liberation of free iodine
(C) partially due to iodine and partially due to CHI3
(D) none of these
Answer ⇒ (B)
14. Which of the following is not correctly matched with its IUPAC name ?
(A) CHF2 CBrCIF : 1-Bromo- 1 -chloro- 1, 2, 2- trifluoroethane
(B) (CCl3)3CCl : 2-(Trichloromethyl)-1, 1, 2, 3, 3- heptachloropropane
(C) CH3C (p-ClC6H4)2 CH(Br)CH3 : 2-Bromo-3, 3-bis (4-chlorophenyl) butane
(D) o-BrC6H4CH (CH3) CH2CH3 : 2-Bromo-1- methylpropylbenzene
Answer ⇒ (B)
15. The reaction
CH2 = CH – CH3 + HBr → 3– CH-CH3 is an example of
(A) nucleophilic addition
(B) free radical addition
(C) electrophilic addition
(D) electrophilic substitution
Answer ⇒ (C)
16.
X and Y in the reaction are
Answer ⇒ (A)
17. Which one of the following is not correct order of boiling points of the alkyl/aryl halides ?
(A) CHCl3 > CH2Cl2
(B) CH3(CH2)3Cl > CH3(CH2)2Cl
(C) (CH3)3CCl > (CH3)2 CHCH2Cl
(D) CH3(CH2)3Cl > CH3CH CHClCH3
Answer ⇒ (C)
18. Which of the following compounds will have highest melting point ?
(A) Chlorobenzene
(B) o-Dichlorobenzene
(C) m-Dichlorobenzene
(D) p-Dichlorobenzene
Answer ⇒ (D)
19. Ethyl alcohol is obtained when ethyl chloride is boiled with
(A) alcoholic KOH
(B) aqueous KOH
(C) water
(D) aqueous KMnO4
Answer ⇒ (B)
20. Which of the following alkyl halides undergoes hydrolysis with aqueous KOH at the fastest rate ?
(A) CH3CH2CH2Cl
(B) CH3CH2Cl
(C) CH3CH2CH2CH2Cl
(D) CH3CH2CH (Br) CH3
Answer ⇒ (D)
21. The alkyl halide is converted into an alcohol by
(A) elimination
(B) dehydrohalogenation
(C) addition
(D) substitution
Answer ⇒ (D)
22. A mixture of 1-chloropropane and 2- chloropropane when treated with alcoholic KOH gives
(A) prop-1-ene
(B) prop-2-ene
(C) a mixture of prop-1-ene and prop-2-ene
(D) propanol
Answer ⇒ (A)
23. Arrange the following alkyl halides in order of dehydrohalogenation
C2H5I, C2H5 Cl, C2H5Br, C2H5F
(A) C2H5H > C2H2Cl > C2H5Br > C2H2I
(B) C2H5I > C2H5Br > C2H5Cl > C2H5F
(C) C2H5I > C2H5Cl > C2H5Br > C2H5F
(D) C2H5F > C2H5I > C2H5Br > C2H5Cl
Answer ⇒ (B)
24. Tertiary alkyi halides are practically inert to substitution by S N2 mechanism because
(A) the carbocation formed is unstable
(B) there is steric hindrance
(C) there is inductive effect
(D) the rate of reaction is faster in S N2 mechanism
Answer ⇒ (B)
25. The order of reactivity of following alcohols with halogen acids is
I. CH3CH2 – CH2 – OH II. CH3CH2 CH – OH
.
(A) I > II > III
(B) III > II > I
(C) II > I > III
(D) I > III > II
Answer ⇒ (B)
26. Identify the compound ‘Y’ in the following reaction :
Answer ⇒ (A)
27. 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
Answer ⇒ (A)
28. Arrange the following compounds in increasing order of their boiling point
I. CH – CH2Br II. CH3CH2CH2CH2Br
(A) II < I < III
(B) I < II < III
(C) III < I < II
(D) III < II <I
Answer ⇒ (C)
29. A primary alkyl halide would prefer to undergo
(A) SN1 reaction
(B) SN2 reaction
(C) α-elimination
(D) racemisation
Answer ⇒ (B)
30. Reaction of C6H5CH2Br with aqueous sodium hydroxide follows
(A) SN1 mechanism
(B) SN2 mechanism
(C) Any of the above two depending upon the temperature of reaction
(D) Saytzeff rule
Answer ⇒ (A)
31. Which of the following compounds will give racemic mixture on nucleophilic substitution by OH-ion ?
(A) I
(B) I, II, III
(C) II, III
(D) I, III
Answer ⇒ (A)
32. A Grignard reagent is prepared by the action of magnesium in dry ether on ?
(A) C2H5OH
(B) C2H6
(C) C2H5Cl
(D) C2H5CN
Answer ⇒ (C)
33. Primary, Secondary and Tertiary alcohols are distinguished by
(A) Oxidation method
(B) Lucas reagent method
(C) Victor Meyer’s method
(D) All of these
Answer ⇒ (D)
34. Ethyl acetate reacts with CH2MgBr to from
(A) Secondary alcohol
(B) Tertiary alcohol
(C) Primary alcohol and Acid
(D) Carboxylic acid
Answer ⇒ (B)