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 → The reaction3– 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

X and Y in the reaction are

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
.                                                                    The order of reactivity of following

The order of reactivity of following

(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 :

Identify the compound

Identify the compound

Answer ⇒ (A)


27. Arrange the following compounds in the increasing order of their densities

Arrange the following compounds in

(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. Arrange the following compounds CH – CH2Br             II. CH3CH2CH2CH2Br

Arrange the following compounds in

(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 ?

Which of the following compounds will

(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)


Class 12th Chemistry Objective Question English

S.N CHEMISTRY OBJECTIVE English Medium
1 SOLID STATE 
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
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