Delhi Public School, Maruti Kunj

XII Chemistry assignment :Haloalkanes & Haloarenes

Part-1

1. Which of the following will show optical is omerism 1 – bromobutane or 2 – bromobutane?

2 Arrange CH3 CH2 CH2 CH2 Br , (CH3)3CBr, CH3CH(CH3)CH2Br in order of

increasing boiling points.

3 Give an example of (a) Fittig reaction (b) Finkelstein reaction.

4 What happens when a) Thionyl chloride acts upon I - propanol. b) Ethanol reacts with PBr3

5 How many aromatic isomers are possible for the formula C7H7Cl ? Write the

structure and name.

6 How is chlorobenzene prepared by (a) direct chlorination b) diazotization method?

7 Write the mechanism of the following reactions:

nBuBr + KCN EtOH-H2O nBuCN

What happens when Cl2 is passed through boiling toluene in presence of sunlight?

8 An acid of M.F C5H10O2 is optically active . What is its structure?

9 P-Chloronitrobenzene undergo nucleophilic substitution faster than chlorobezene .

Explain giving the resonating structure as well.

10 Write the reagent for the following conversion

Br H-C C -H

Br

11 Predict all the alkenes that would be formed by dehydrohalogenation of the following

halides with sodium ethoxide in ethanol and identify the major alkene

(i) 1-Bromo-1-methylcyclohexane (ii) 2-Chloro-2-methylbutane

(iii) 3-Bromo-2,2,3- trimethylpentane.

12 Primary alkyl halide C4H9Br (a) reacted with alcoholic KOH to give compound (b).

Compound (b) is reacted with HBr to give (c) which is an isomer of (a). When (a)

Is reacted with Na metal , it gives a compound (d), C8H18 which is different from

The compound formed when n-butyl bromide is reacted with Na. Give the structural

Formula of (a) and write the equations for all the reactions.

13 An optically active compound having M.F C7H15Br react with aqueous KOH to

give a racemic mixture of products. Write the mechanism involved for this reaction.

14 Which one of the following reacts faster in an SN1 reaction &why ?

CH3CH2CH2Br or CH3CHBrCH3

15 An alkyl bromide produces a single alkene when it reacts with sodium ethoxide

and ethanol . This alkene on hydrogenation produces 2-methylbutane. Identify

the alkyl nhalide.

16 Explain why

(i) the dipole moment of chlorobenzene is lower than that of cyclohexyl chloride?

(ii) haloalkanes with KCN gives alkyl cyanides but with AgCN gives isocyanides.

(iii) C-Cl bond in aryl halide is shorter than C-Cl bond in alkyl halide.

17 In the following pairs of halogen compounds , which would undergo SN2 reaction faster?

CH2Cl and Cl CH3CH2I and CH3CH2Cl

18 Convert:

(i) Ethyl chloride into ethyl iodide . (ii) Chlorobenzene to phenol.

(iii) Methyl bromide to acetone. (iv) Propene to 1-nitro propane

(v) Benzene to 4-bromobenzene

Delhi Public School Maruti Kunj

Class Xll Haloalkanes and Haloarenes

Part-2

1 Write the IUPAC name of the following:

C H3 CH3

H H

C H3

Br

2 Among the isomeric alkanes of M.F C5H12 , identify the one that on photochemical

chlorination yields a single monochloride.

3 Arrange the following compounds in order of increasing boiling points.:

1-Chloropropane , isopropyl chloride , 1-Chlorobutane

4 Draw enantiomers of 2-Bromopropanoic acid

5 Out of the following which is more reactive towards SN1 reaction and why?

Cl Cl

CH3

6 How many aromatic isomers are possible for the formula C7 H7 Cl ? Write the structure

and names.

7 An alkyl halide (A), on reaction with magnesium in dry ether followed by treatment with

ethanol gave 2-methyl propane. Write the structure of (A) and all the reactions involved.

8 With the help of resonating structures explain why P-Nitrochlorobenzene is more reactive

than chlorobenzene towards nucleophilic substitution reaction.

9 Arrange the compounds of each set in order of reactivity towards SN2 displacement.

(i) 2-Bromo-2-methylbutane, 1-Bromopentane , 2-Bromopentane

(ii) 1-Bromo-3-methylbutane , 2-Bromo-2-methylbutane, 2-Bromo-3-methylbutane

10 How will you carry out the following conversions:

(i) Ethanol to propanenitrile

(ii) benzene to diphenyl

(iii) Toluene to bezyl alcohol

11 What happens when:

(i) n-Propylchloride is heated with alc KOH.

(ii) Ethyl bromide is treated with NaI in presence of acetone.

(iii) When benzene diazonium chloride is heated with KI.