Friday, 29 January 2021

CBSE Class 12 Chemistry - MCQ and Online Tests - Unit 10 - Haloalkanes and Haloarenes

CBSE Class 12 Chemistry – MCQ and Online Tests – Unit 10 – Haloalkanes and Haloarenes

Every year CBSE conducts board exams for 12th standard. These exams are very competitive to all the students. So our website provides online tests for all the 12th subjects. These tests are also very effective and useful for those who preparing for competitive exams like NEET, JEE, CA etc. It can boost their preparation level and confidence level by attempting these chapter wise online tests.

These online tests are based on latest CBSE Class 12 syllabus. While attempting these our students can identify the weak lessons and continuously practice those lessons for attaining high marks. It also helps to revise the NCERT textbooks thoroughly.


 

CBSE Class 12 Chemistry – MCQ and Online Tests – Unit 10 – Haloalkanes and Haloarenes

Question 1.
Criteria for purity of organic solid is
(a) boiling point
(b) melting point
(c) specific gravity
(d) none of these

Answer

Answer: (b) melting point


Question 2.
Hybridisation of carbon in ethane is
(a) sp3
(b) sp2
(c) sp
(d) sp3d2

Answer

Answer: (a) sp3


Question 3.
The negative part of the addendum (the molecule to be added) adds on the carbon atom of the double bond containing the least number of hydrogen atoms. This rule is known as
(a) Saytzeffs rule
(b) Peroxide rule
(c) Markovnikov’s rule
(d) van’t hoff rule

Answer

Answer: (c) Markovnikov’s rule


Question 4.
General formula of Alkene is
(a) CnH2n
(b) CnH2n+2
(c) CnH2n-2
(d) none of these

Answer

Answer: (a) CnH2n


Question 5.
Number of π bonds in ethyne is
(a) 1
(b) 2
(c) 3
(d) 4

Answer

Answer: (b) 2


Question 6.
Organic compound must contain an element
(a) oxygen
(b) carbon
(c) hydrogen
(d) nitrogen

Answer

Answer: (b) carbon


Question 7.
Which of the following is not correctly matched with its IUPAC name?
(a) CHF2CBrClF : 1-Bromo-1-chIoro-1, 2, 2-trifluoroethane
(b) (CCl3)3CCl : 2-(Trichloromethyl)-1, 1, 2, 3, 3-heptachloropropane
(c) CH3C (p-ClC6H4)2CH(Br)CH3 : 2-Bromo-3, 3-bis (4- chlorophenyl) butane
(d) o-BrC6H4CH (CH3) CH2CH3 : 2-Bromo-l- methylpropylbenzene

Answer

Answer: (b) (CCl3)3CCl : 2-(Trichloromethyl)-1, 1, 2, 3, 3-heptachloropropane


Question 8.
Which of the following compounds can yield only one monochlorinafed product upon free radical chlorination?
(a) 2, 2-Dimethylpropane
(b) 2-Methylpropane
(c) 2-Methylbutane
(d) n-Butane

Answer

Answer: (a) 2, 2-Dimethylpropane


Question 9.
Which of the following molecules has highest dipole moment?
(a) CH3Cl
(b) CH2Cl2
(c) CHCl5
(d) CCl4

Answer

Answer: (a) CH3Cl


Question 10.
The compound having general formula CnH2n+2 is
(a) Alkene
(b) Alkyne
(c) Alkane
(d) none of these

Answer

Answer: (c) Alkane


Question 11.
Halogen acids react with alcohols to form alkyl halides. The reaction follows a nucleophilic substitution mechanism. What will be the product of the following reaction?
MCQ Questions for Class 12 Chemistry Chapter 10 Haloalkanes and Haloarenes with Answers 2
(d) CH3CH2CH2CH2CH2Cl

Answer

Answer: (a)


Question 12.
MCQ Questions for Class 12 Chemistry Chapter 10 Haloalkanes and Haloarenes with Answers 3
X and Y in the reaction are
MCQ Questions for Class 12 Chemistry Chapter 10 Haloalkanes and Haloarenes with Answers 4

Answer

Answer: (a)


Question 13.
Good conductor of electricity and heat is
(a) Anthracite coke
(b) Diamond
(c) Graphite
(d) Charcoal

Answer

Answer: (c) Graphite.

Question 14.
Bromination of methane in presence of sunlight is a
(a) nucleophilic substitution
(b) free radical substitution
(c) electrophilic substitution
(d) nucleophilic addition

Answer

Answer: (b) free radical substitution


Question 15.
Which one of the following is not correct order of boiling .points of the alkyl/aryl halides?
(a) CHCl3 > CH2Cl2
(b) CH3(CH2)3CI > CH3(CH2)2Cl
(c) (CH3)3CCl > (CH3)2CHCH2Cl
(d) CH3(CH2)3Cl > CH3CH2CHClCH3

Answer

Answer: (c) (CH3)3CCl > (CH3)2CHCH2Cl


Question 16.
Which of the following reactions follows Markovnikov’s rule?
(a) C2H4 + HBr
(b) C3H6 + Cl6
(c) C3H6 + HBr
(d) C3H6 + Br2

Answer

Answer: (c) C3H6 + HBr


Question 17.
Which of the following compounds has the highest boiling point?
(a)CH3CH2CH2Cl
(b) CH3CH2CH2CH2Cl
(c) CH3CH(CH3)CH2Cl
(d) (CH3)3CCl

Answer

Answer: (b) CH3CH2CH2CH2Cl


Question 18.
Arrange the following compounds in-decreasing order of their boiling points
(i) CH3Br
(ii) CH3CH2Br
(iii) CH3CH2CH2Br
(iv) CH2CH2CH2CH2Br
(a) (i) > (ii) > (iii) > (iv)
(b) (iv) > (iii) > (ii) > (i)
(c) (i) > (iii) > (ii) > (iv)
(d) (iii) > (iv) > (i) > (ii)

Answer

Answer: (b) (iv) > (iii) > (ii) > (i)


Question 19.
Alkyl halides are immiscible in water though they are polar because
(a) they react with water to give alcohols
(b) they cannot form hydrogen bonds with water
(c) C -X bond cannot be broken easily
(d) they are stable compounds and are not reactive

Answer

Answer: (b) they cannot form hydrogen bonds with water


Question 20.
The reaction of toluene with chlorine in presence of FeCl3 gives predominantly.
(a) amixture of o-and p-chlorotoluene
(b) benzyl chloride
(c) m-chlorotuluene
(d) benzoyl chloride

Answer

Answer: (a) amixture of o-and p-chlorotoluene


Question 21.
Which of the following compounds will have highest melting point?
(a) Chlorobenzene
(b) o-Dichlorobenzene
(c) m-Dichlorobenzene
(d) p-Dichlorobenzene

Answer

Answer: (d) p-Dichlorobenzene


Question 22.
Ethyl alcohol is obtained when ethyl chloride is boiled with
(a) alcoholic KOH
(b) aqueous KOH
(c) water
(d) aqueous KMnO4

Answer

Answer: (b) aqueous KOH


Question 23.
The hybridisation of carbon in diamond is
(a) sp3
(b) sp2
(c) sp
(d) dsp2

Answer

Answer: (a) sp3


Question 24.
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

Answer: (d) CH3CH2CH (Br) CH3


Question 25.
The reaction
MCQ Questions for Class 12 Chemistry Chapter 10 Haloalkanes and Haloarenes with Answers 1
is an example of
(a) nucleophilic addition
(b) free radical addition
(c) electrophilic addition
(d) electrophilic substitution

Answer

Answer: (c) electrophilic addition


Question 26.
Alkene gives which of the following reactions?
(a) Addition reaction
(b) Substitution reaction
(c) Both (a) and (b)
(d) None of these

Answer

Answer: (c) Both (a) and (b)


Question 27.
Butane nitrile can be prepard by heating.
(a) propyl alcohol with KCN
(b) butyl chloride with KCN
(c) butyl alcohol with KCN
(d) propyl chloride with KCN

Answer

Answer: (d) propyl chloride with KCN


Question 28.
Which of the following reactions will give the major and minor products?
MCQ Questions for Class 12 Chemistry Chapter 10 Haloalkanes and Haloarenes with Answers 5
(a) (a) is major product and (b) is minor product
(b) (a) is minor product and (b) is major product
(c) Both (a) and (b) are major products
(d) Only (b) is formed and (a) is not formed

Answer

Answer: (a) (a) is major product and (b) is minor product


Question 29.
Which of the following is the most reactive towards nucleophilic substitution reaction?
(a) ClCH2– CH = CH2
(b) CH2 = CH-Cl
(c) CH3CH = CH-Cl
(d) C6H6Cl

Answer

Answer: (a) ClCH2-CH = CH2


Question 30.
MCQ Questions for Class 12 Chemistry Chapter 10 Haloalkanes and Haloarenes with Answers 6
The final product in the reaction is
(a) CH3OH
(b) HCOOH
(c) CH3OH
(d) CH3COOH

Answer

Answer: (d) CH3COOH


Question 31.
The end product (Q) is in the following sequence of reaction
MCQ Questions for Class 12 Chemistry Chapter 10 Haloalkanes and Haloarenes with Answers 7

Answer

Answer: (c)


Question 32.
Methyl bromide reacts with AgF to give methyl fluoride and silver bromide. This reaction is called
(a) Fittig reaction
(b) Swarts reaction
(c) Wurtz reaction
(d) Finkelstein reaction

Answer

Answer: (b) Swarts reaction


Question 33.
The alkyl halide is converted into an alcohol by
(a) elimination
(b) dehydrohalogenation
(c) addition
(d) substitution

Answer

Answer: (d) substitution


Question 34.
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

Answer: (a) prop-1-ene


Question 35.
Valency of carbon is
(a) 1
(b) 2
(c) 3
(d) 4

Answer

Answer: (d) 4


Question 36.
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

Answer: (c) Graphite


Question 37.
In SN2 reactions with the sequence of bond breaking and bond formation is as follows
(a) bond breaking is followed by formation
(b) bond formation is followed by breaking
(c) bond breaking and formation are simultaneously
(d) bond breaking and formation take place randomly

Answer

Answer: (c) bond breaking and formation are simultaneously


Question 38.
Single bond length between carbon-carbon is
(a) 1.34 Å
(b) 1.20 Å
(c) 1.54 Å
(d) none of these

Answer

Answer: (c) 1.54 Å


Question 39.
Grignard reagents are formed by the reaction of alkyl halides by warming
(a) with alcoholic solution
(b) with MgCl2
(c) Mg in presence of dry ether
(d) with MgCO3

Answer

Answer: (c) Mg in presence of dry ether


Question 40.
An alkyl halide, RX reacts with KCN to given propane nitrile, RX is
(a) C3H7Br
(b) C4H9Br
(c) C2H5Br
(d) C5H11Br

Answer

Answer: (c) C2H5Br


 

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