Match the reactions given in Column I with the names given in Column II
(i-> b), (ii —> a), (iii —> d), (iv — » c)
(i) A mixture of an alkyl halide and aryl halides gives an alkylarene when treated with sodium in dry ether and this is called Wurtz-Fittig reaction.
(ii) Aryl halides give analogous compounds when treated with sodium in dry ether, in which two aryl groups are joined together. It is called Fittig reaction.
(iii) Diazonium salt when treated with cuprous chloride or cuprous bromide gives chlorobenzene or bromobenzene. The reaction is known as Sandmeyer's reaction.
(iv) Alkyl iodides are prepared by the reaction of alkyl chlorides with sodium iodide in dry acetone. The reaction is known as Finkelstein reaction.
p-Dichlorobenzene has higher m.p. and lower solubility than those of o-and m-isomers. Discuss.
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.
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.
How can you obtain iodoethane from ethanol when no other iodine containing reagent except Nal is available in the laboratory?
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.
Which alkyl halide from the following pairs would you expect to react more rapidly by an SN2 mechanism? Explain your answer.
What happens when .
(i)n-butyi 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.
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 compounds (a) and (b) will not react with a mixture of NaBr and H2S04. Explain why?
What are the IUPAC name of the insecticide DDT and benzenehexachloride?
Why is their use banned in India and other countries?
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.
Benzene < Chlorobenzene < Dichlorobenzene < Bromochlorobenzene Arrange the following compounds in increasing order of their boiling points
Why is it necessary to avoid even traces of moisture during the use of a Grignard reagent?
Assertion (A): Hydrolysis of (-)-2-bromooctane proceeds with inversion of configuration.
Reason (R): This reaction proceeds through the formation of a carbocation.
Write structures of the following compounds:
(i) 2-Chloro-3-methylpentane
(ii) 1-Chloro-4-ethylcydohexane
(iii) 4-tert. Butyl-3-iodoheptane
(iv) 1,4-Dibromobut-2-ene
(v) 1-Bromo-4-sec. butyl-2-methylbenzene.
In the following pairs of halogen compounds, which compound undergoes faster SN1 reaction?
Questions on the basis of the following reaction:
Which of the following statements are correct about the mechanism of this reaction?
(a) Acarbocation will be formed as an intermediate in the reaction.
(b) OH– will attach the substrate (iii) from one side and Cl– will leave it simultaneously from other side.
(c) An unstable intermediate will be formed in which OH– and Cl– will be attached by weak bonds.
(d) Reaction proceeds through SN1 mechanism.
Haloalkanes contain halogen atom(s) attached to sp3 hybridised carbon atom of an alkyl group. Identify haloalkane from the following compounds.
(a) 2-Bromopentane (b) Vinyl chloride (chloroethene)
(c) 2-Chloroacetophenone (d) Trichloromethane
Alkyl halides are prepared from alcohol by treating with
(a) HCl + ZnCl2 (b) RedP + Br2
(c) H2SO4 + KI (d) all the above
tert-Butylbromide reacts with aq. NaOH by SN1 mechanism while n-butylbromide reacts by SN2 mechanism. Why?
Assertion (A): Nitration of chlorobenzene leads to the formation of m-nitrochlorobenzene.
Reason (R): N02 group is a w-directing group.
In the following pairs of halogen compounds, which compound undergoes faster SN1 reaction?
A hydrocarbon C5H10 does not react with chlorine in dark but gives a single monochloro compound C5H9Cl in bright sunlight. Identify the hydrocarbon.
A hydrocarbon C5H10 does not react with chlorine in dark but gives a single monochloro compound C5H9CI in bright sunlight. Identify the hydrocarbon.
Predict all the alkenes that would be formed by dehydrohalogenationof the following halides with sodium ethoxide in ethdnol and identify the major alkene:
(i)1-Bromo-l-methylcyclohexane
(ii)2-Chloro-2-methylbutane.
(ill) 2,2,3-Trimethyl-3-bromopentane.
Predict all the alkenes that would be formed by dehydrohalogenationof the following halides with sodium ethoxide in ethdnol and identify the major alkene:
(i)1-Bromo-l-methylcyclohexane
(ii)2-Chloro-2-methylbutane.
(ill) 2,2,3-Trimethyl-3-bromopentane.
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
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.
Draw other resonance structures related to the following structure and find out whether the functional group present in the molecule is ortho, para directing or meta directing.
Identify the products A and B formed in the following reaction:
CH3-CH2-CH=CH-CH3 + HCl–>A+B
A hydrocarbon of molecular mass 72 g mol-1 gives a single monochloro derivative and two dichloro derivatives on photo chlorination. Give the structure of the hydrocarbon.
Assertion (A): Presence of a nitro group at ortho or para position increases Reason (R): Nitro gjoup, being an electron withdrawing group decreases the electron density over the benzene ring.
