Write structures of different dihalogen derivatives of propane.
Four isomers are possible. These are :
Match the structures of compounds given in Column I with the classes of compounds given in Column II.
Chlorobenzene is formed by reaction of chlorine with benzene in the presence of AlCl3. Which of the following species attacks the benzene ring in this reaction?
(a) CP (b) Cl+ (c) AlCl3 (d) [AlCl4]–
How will you bring about the following conversions?
(i)Ethanol to but-l-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-l-ene to but-2-ene
(ix)1-Chlorobutane to n-octane (x)Benzene to biphenyl
Elimination reactions (especially Beta-elimination) are as common as the nucleophilic substitution reaction in case of alkyl halides. Specify the reagents used in both cases.
Which of the following compounds will give racemic mixture on nucleophilic substitution by OH ion?
Alkyl halides are prepared from alcohol by treating with
(a) HCl + ZnCl2 (b) RedP + Br2
(c) H2SO4 + KI (d) all the above
Diphenyls are potential threat to the environment. How are these produced from arylhalides?
Some alkylhalides undergo substitution whereas some undergo elimination reaction on treatment with bases. Discuss the structural features of alkyl halides with the help of examples which are responsible for this difference.
Ethylene chloride and ethylidene chloride are isomers. Identify the correct statements.
(a) Both the compounds form same product on treatment with alcoholic KOH
(b) Both the compounds from same product on treatment with aqueous NaOH
(c) Both the compounds form same product on reduction
(d) Both the compounds are optically active
Which of the following are secondary bromides?
(a) (CH3),CHBr (b) (CH3)3C CH2Br
(c) CH3CH(Br)CH2CH3 (d) (CH3)2CBrCH2CH3
Alkyl fluorides are synthesized by heating an alkyl chloride/bromide in presence of or
(a) CaF2 (b) CoF2 (c) Hg,F2 (d) NaF
What are the IUPAC name of the insecticide DDT and benzenehexachloride?
Why is their use banned in India and other countries?
Which of the following statements are correct about the reaction intermediate?
(a) Intermediate (iii) is unstable because in this carbon is attached to 5 atoms.
(b) Intermediate (iii) is unstable because carbon atom is sp2 hybridised.
(c) Intermediate (iii) is stable because carbon atom is sp2 hybridised.
(d) Intermediate (iii) is less stable than the reactant (ii).
Which of the following statements are correct about the kinetics of this reaction?
(a) The rate of reaction depends on the concentration of only (ii).
(b) The rate of reaction depends on concentration of both (i) and (ii).
(c) Molecularity of reaction is one.
(d) Molecularity of reaction is two.
Assertion (A): tert-Butyl bromide undergoes Wurtz reaction to give 2, 2, 3, 3-tetramethylbutane.
Reason (R): In Wurtz reaction, alkyl halides react with sodium in dry ether to give hydrocarbon containing double the number of carbon atoms present in the halide.
Write the equations for the preparation of 1-iodoobutanefrom (i)1-butanol (ii)1-chlorobutane (iii) but-l-ene.
Assertion (A): The boiling points of alkyl halides decrease in the order: RI > RBr > RCl > RF
Reason (R): The boiling points of alkyl chlorides, bromides and iodides are considerably higher than that of the hydrocarbon of comparable molecular mass.
Some halogen containing compounds are useful in daily life. Some compounds of this class are responsible for exposure of flora and fauna to more and more of UV light which causes destruction to a great extent. Name the class of these halo compounds. In your opinion, what should be done to minimize harmful effects of these compounds.
Which of the following compounds can be classified as aryl halides ? (a) p-ClC6H4CH2CH(CH3)2 (b) p-CH3CHCl(C6H4)CH2CH3 (c) o-BrH2CC6H4CH(CH3)CH2CH3 (d) C6H5Cl
Discuss the nature of C – X bond in the haloarenes.
C – X bond in haloarenes is extremely less reactive towards nucleophilic
Assertion (A): Hydrolysis of (-)-2-bromooctane proceeds with inversion of configuration.
Reason (R): This reaction proceeds through the formation of a carbocation.
In the following pairs of halogen compounds, which compound undergoes faster SN1 reaction?
Which compound in each of the following-pairs . will react faster in SN2 reaction with -OH? (i)CH3Br or CH3I
(ii)(CH3)3CCl or CH3Cl
Molecules whose mirror image is non superimposable over them are known as chiral. Which of the following molecule is chiral in nature?
(a) 2-Bromobutane (b) 1-Bromobutane
(c) 2-Bromopropane (d) 2-Bromopropan-2-ol
Classify the following compounds as primary, secondary and tertiary halides.
(i) l-Bromobut-2-ene
(iii) 2-Bromo-2-methylpropane
Write the structures and names of the compounds formed when compound ‘A' with molecular formula, C7H8 is treated with Cl2 in the presence of FeCl3.
tert-Butylbromide reacts with aq. NaOH by SN1 mechanism while n-butylbromide reacts by SN2 mechanism. Why?
In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct option out of the choices given below each question:
(a)Assertion and Reason both are correct and Reason is the correct explanation of Assertion.
(b)Assertion and Reason both are wrong.
(c)Assertion is correct but Reason is wrong.
(d)Assertion is wrong but Reason is correct.
(e)Assertion and Reason both are correct statements but Reason is not the correct explanation of Assertion.
Assertion (A): Phosphorus chlorides (tri and penta) are preferred over thionyl chloride for the preparation of alkyl chlorides from alcohols.
Reason (R): Phosphorus chlorides give pure alkyl halides.
Assertion (A): In monohaloarenes, further electrophilic substitution occurs at ortho and para positions.
Reason (R): Halogen atom is a ring deactivator.
Assertion (A): Aryl iodides can be prepared by reaction of arenas with iodine in the presence of an oxidizing agent.
Reason (R): Oxidising agent oxidises I2 into HI.
Assertion (A): It is difficult to replace chlorine by -OH in chlorobenzene in comparison to that in chloroethane.
Reason (R): Chlorine-carbon (C – Cl) bond in chlorobenzene has a partial double bond character due to resonance.
