Chemistry · Textbook solutions
Haloalkanes and Haloarenes
Every solved example, exercise, and miscellaneous question — in the order the textbook teaches them. · 40 questions
Worked Examples
9 q
Solved Examples
Worked · 9
- Eg 6.1Draw the structures of all the eight structural isomers that have the molecular formula . Name each isomer according to IUPAC system and classify them as primary, secondary or tertiary bromide.
- Eg 6.2Write IUPAC names of the following: (i) (ii) (iii) (iv) (v) (vi)
- Eg 6.3Identify all the possible monochloro structural isomers expected to be formed on free radical monochlorination of .
- Eg 6.4Write the products of the following reactions: (i) (ii) (iii)
- Eg 6.5Haloalkanes react with KCN to form alkyl cyanides as main product while AgCN forms isocyanides as the chief product. Explain.
- Eg 6.6In the following pairs of halogen compounds, which would undergo reaction faster? (i) (chloromethylcyclohexane) and (chlorocyclohexane) (ii) (1-iodobutane) and (1-chlorobutane)
- Eg 6.7Predict the order of reactivity of the following compounds in and reactions: (i) The four isomeric bromobutanes (ii) , , ,
- Eg 6.8Identify chiral and achiral molecules in each of the following pair of compounds. (Wedge and Dash representations according to Class XI. (i) (i) (ii) (ii) (i) (pentan-2-ol) (ii) (pentan-3-ol) (iii) (i) (ii)
- Eg 6.9Although chlorine is an electron withdrawing group, yet it is ortho-, para- directing in electrophilic aromatic substitution reactions. Why?
Intext Questions
9 q
- Intext 6.1Write structures of the following compounds: (i) 2-Chloro-3-methylpentane (ii) 1-Chloro-4-ethylcyclohexane (iii) 4-tert. Butyl-3-iodoheptane (iv) 1,4-Dibromobut-2-ene (v) 1-Bromo-4-sec. butyl-2-methylbenzene.
- Intext 6.2Why is sulphuric acid not used during the reaction of alcohols with KI?
- Intext 6.3Write structures of different dihalogen derivatives of propane.
- Intext 6.4Among the isomeric alkanes of molecular formula , identify the one that on photochemical chlorination yields (i) A single monochloride. (ii) Three isomeric monochlorides. (iii) Four isomeric monochlorides.
- Intext 6.5Draw the structures of major monohalo products in each of the following reactions: (i) cyclohexanol (ii) 1-ethyl-4-nitrobenzene (iii) 4-(hydroxymethyl)phenol (iv) 1-methylcyclohex-1-ene (v) (vi) cyclohexene
- Intext 6.6Arrange each set of compounds in order of increasing boiling points. (i) Bromomethane, Bromoform, Chloromethane, Dibromomethane. (ii) 1-Chloropropane, Isopropyl chloride, 1-Chlorobutane.
- Intext 6.7Which alkyl halide from the following pairs would you expect to react more rapidly by an mechanism? Explain your answer. (i) or (ii) or (iii) or
- Intext 6.8In the following pairs of halogen compounds, which compound undergoes faster reaction? (i) (2-chloro-2-methylpropane) and (3-chloropentane) (ii) (2-chloroheptane) and (1-chlorohexane)
- Intext 6.9Identify A, B, C, D, E, R and in the following: (bromocyclohexane) (2,2,3,3-tetramethylbutane)
Exercises
22 q
- Ex 6.1Name the following halides according to IUPAC system and classify them as alkyl, allyl, benzyl (primary, secondary, tertiary), vinyl or aryl halides: (i) (ii) (iii) (iv) (v) (vi) (vii) (viii) (ix) (x) (xi) (xii)
- Ex 6.2Give the IUPAC names of the following compounds: (i) (ii) (iii) (iv) (v) (vi)
- Ex 6.3Write the structures of the following organic halogen compounds. (i) 2-Chloro-3-methylpentane (ii) -Bromochlorobenzene (iii) 1-Chloro-4-ethylcyclohexane (iv) 2-(2-Chlorophenyl)-1-iodooctane (v) 2-Bromobutane (vi) 4-tert-Butyl-3-iodoheptane (vii) 1-Bromo-4-sec-butyl-2-methylbenzene (viii) 1,4-Dibromobut-2-ene
- Ex 6.4Which one of the following has the highest dipole moment? (i) (ii) (iii)
- Ex 6.5A hydrocarbon does not react with chlorine in dark but gives a single monochloro compound in bright sunlight. Identify the hydrocarbon.
- Ex 6.6Write the isomers of the compound having formula .
- Ex 6.7Write the equations for the preparation of 1-iodobutane from (i) 1-butanol (ii) 1-chlorobutane (iii) but-1-ene.
- Ex 6.8What are ambident nucleophiles? Explain with an example.
- Ex 6.9Which compound in each of the following pairs will react faster in reaction with ? (i) or (ii) or
- Ex 6.10Predict 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) 2,2,3-Trimethyl-3-bromopentane.
- Ex 6.11How will you bring about the following conversions? (i) Ethanol to but-1-yne (ii) Ethane to bromoethene (iii) Propene to 1-nitropropane (iv) Toluene to benzyl alcohol (v) Propene to propyne (vi) Ethanol to ethyl fluoride (vii) Bromomethane to propanone (viii) But-1-ene to but-2-ene (ix) 1-Chlorobutane to n-octane (x) Benzene to biphenyl.
- Ex 6.12Explain why (i) the dipole moment of chlorobenzene is lower than that of cyclohexyl chloride? (ii) alkyl halides, though polar, are immiscible with water? (iii) Grignard reagents should be prepared under anhydrous conditions?
- Ex 6.13Give the uses of freon 12, DDT, carbon tetrachloride and iodoform.
- Ex 6.14Write the structure of the major organic product in each of the following reactions: (i) (ii) (iii) (iv) (v) (vi) (vii) (viii)
- Ex 6.15Write the mechanism of the following reaction:
- Ex 6.16Arrange the compounds of each set in order of reactivity towards displacement: (i) 2-Bromo-2-methylbutane, 1-Bromopentane, 2-Bromopentane (ii) 1-Bromo-3-methylbutane, 2-Bromo-2-methylbutane, 2-Bromo-3-methylbutane (iii) 1-Bromobutane, 1-Bromo-2,2-dimethylpropane, 1-Bromo-2-methylbutane, 1-Bromo-3-methylbutane.
- Ex 6.17Out of and , which is more easily hydrolysed by aqueous KOH.
- Ex 6.18-Dichlorobenzene has higher m.p. than those of - and -isomers. Discuss.
- Ex 6.19How the following conversions can be carried out? (i) Propene to propan-1-ol (ii) Ethanol to but-1-yne (iii) 1-Bromopropane to 2-bromopropane (iv) Toluene to benzyl alcohol (v) Benzene to 4-bromonitrobenzene (vi) Benzyl alcohol to 2-phenylethanoic acid (vii) Ethanol to propanenitrile (viii) Aniline to chlorobenzene (ix) 2-Chlorobutane to 3, 4-dimethylhexane (x) 2-Methyl-1-propene to 2-chloro-2-methylpropane (xi) Ethyl chloride to propanoic acid (xii) But-1-ene to n-butyliodide (xiii) 2-Chloropropane to 1-propanol (xiv) Isopropyl alcohol to iodoform (xv) Chlorobenzene to -nitrophenol (xvi) 2-Bromopropane to 1-bromopropane (xvii) Chloroethane to butane (xviii) Benzene to diphenyl (xix) tert-Butyl bromide to isobutyl bromide (xx) Aniline to phenylisocyanide
- Ex 6.20The treatment of alkyl chlorides with aqueous KOH leads to the formation of alcohols but in the presence of alcoholic KOH, alkenes are major products. Explain.
- Ex 6.21Primary alkyl halide (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 sodium metal it gives compound (d), which is different from the compound formed when n-butyl bromide is reacted with sodium. Give the structural formula of (a) and write the equations for all the reactions.
- Ex 6.22What happens when (i) n-butyl chloride is treated with alcoholic KOH, (ii) bromobenzene is treated with Mg in the presence of dry ether, (iii) chlorobenzene is subjected to hydrolysis, (iv) ethyl chloride is treated with aqueous KOH, (v) methyl bromide is treated with sodium in the presence of dry ether, (vi) methyl chloride is treated with KCN?