10. HALOALKANES AND HALOARENES Objective
10. HALOALKANES AND HALOARENES
Download 1. Good conductor of electricity and heat is
(A) Anthracite coke
(B) Diamond
(C) Graphite
(D) Charcoal
Answer тЗТ (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 тЗТ (C)
3. The hybridisation of carbon in diamond is
(A) sp3
(B) sp2
(c) sp
(D) dsp2
Answer тЗТ (A)
4. Organic compound must contain an element
(A) oxygen
(B) carbon
(C) hydrogen
(D) nitrogen
Answer тЗТ (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 тЗТ (C)
6. Single bond length between carbon-carbon is
(A) 1.34 ├Е
(B) 1.20 ├Е
(C) 1.54 ├Е
(D) none of these
Answer тЗТ (C)
7. Valency of carbon is
(A) 1
(B) 2
(C) 3
(D) 4
Answer тЗТ (D)
8. Criteria for purity of organic solid is
(A) boiling point
(B) melting point
(C) specific gravity
(D) none of these
Answer тЗТ (B)
9. General formula of Alkene is
(A) CnH2n
(B) CnH2n + 2
(C) CnH2n – 2
(D) none of these
Answer тЗТ (A)
10. Hybridisation of carbon in ethane is
(A) sp3
(B) sp2
(C) sp
(D) sp3d2
Answer тЗТ (A)
11. Number of ╧А bonds in ethyne is
(A) 1
(B) 2
(C) 3
(D) 4
Answer тЗТ (B)
12. The compound having general formula CnH2n + 2 is
(A) Alkene
(B) Alkyne
(C) Alkane
(D) none of these
Answer тЗТ (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 тЗТ (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 тЗТ (B)
15. The reaction
CH2 = CH тАУ CH3 + HBr тЖТ 
3– CH-CH3 is an example of
(A) nucleophilic addition
(B) free radical addition
(C) electrophilic addition
(D) electrophilic substitution
Answer тЗТ (C)
16. 
X and Y in the reaction are
Answer тЗТ (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 тЗТ (C)
18. Which of the following compounds will have highest melting point ?
(A) Chlorobenzene
(B) o-Dichlorobenzene
(C) m-Dichlorobenzene
(D) p-Dichlorobenzene
Answer тЗТ (D)
19. Ethyl alcohol is obtained when ethyl chloride is boiled with
(A) alcoholic KOH
(B) aqueous KOH
(C) water
(D) aqueous KMnO4
Answer тЗТ (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 тЗТ (D)
21. The alkyl halide is converted into an alcohol by
(A) elimination
(B) dehydrohalogenation
(C) addition
(D) substitution
Answer тЗТ (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 тЗТ (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 тЗТ (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 тЗТ (B)
25. The order of reactivity of following alcohols with halogen acids is
I. CH3CH2 – CH2 – OH II. CH3CH2 CH – OH
.┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а ┬а 
(A) I > II > III
(B) III > II > I
(C) II > I > III
(D) I > III > II
Answer тЗТ (B)
26. Identify the compound ‘Y’ in the following reaction :
Answer тЗТ (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 тЗТ (A)
28. Arrange the following compounds in increasing order of their boiling point
I. 
CH тАУ CH2Br┬а ┬а ┬а ┬а ┬а ┬а ┬аII. CH3CH2CH2CH2Br
(A) II < I < III
(B) I < II < III
(C) III < I < II
(D) III < II <I
Answer тЗТ (C)
29. A primary alkyl halide would prefer to undergo
(A) SN1 reaction
(B) SN2 reaction
(C) ╬▒-elimination
(D) racemisation
Answer тЗТ (B)
30. Reaction of C6H5CH2Br with aqueous sodium hydroxide follows
(A) SN1 mechanism
(B) SN2┬аmechanism
(C) Any of the above two depending upon the temperature of reaction
(D) Saytzeff rule
Answer тЗТ (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 тЗТ (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 тЗТ (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 тЗТ (D)
34. Ethyl acetate reacts with CH2MgBr to from
(A) Secondary alcohol
(B) Tertiary alcohol
(C) Primary alcohol and Acid
(D) Carboxylic acid
Answer тЗТ (B)
Class 12th Chemistry Objective Question English
| S.N | CHEMISTRY OBJECTIVE English Medium |
| 1 | SOLID STATE┬а |
| 2 | SOLUTION |
| 3 | ELECTROCHEMISTRY |
| 4 | CHEMICAL KINETICS |
| 5 | SURFACE CHEMISTRY |
| 6 | GENERAL PRINCIPLES & PROCESSES OF ISOLATION OF ELEMENTS |
| 7 | THE P-BLOCK ELEMENTS |
| 8 | THE D- AND f-BLOCK ELEMENTS |
| 9 | CO-ORDINATION COMPOUNDS |
| 10 | HALOALKANES AND HALOARENES |
| 11 | ALCOHOLS, PHENOLS AND ETHERS |
| 12 | ALDEHYDES, KETONES AND CARBOXYLIC ACIDS |
| 13 | AMINES |
| 14 | BIOMOLECULES |
| 15 | POLYMERS |
| 16 | CHEMISTRY IN EVERYDAY LIFE |
