HALOGEN CONTAINING COMPOUNDSIntroduction of Halogen containing compoundsQ.1 How many structural isomers are possible for a compound with molecular formula C3H7Cl

(a.1) 2 (b.1) 4 (c.1) 7 (d.1) 9Q.2 In CH3CH2Br, % of Br is .....

(a.2) 80 (b.2) 75 (c.2) 50 (d.2) none of theseQ.3 Gem- dibromide is ......

(a.3) CH3CH(Br)OH(Br)CH3 (b.3) CH3CBr2CH3

(c.3) CH2(Br)CH2CH2 (d.3) CH2BrCH2BrQ.4 Ethylidene dibromide is....

(a.4) CH3 -CH2 -Br(b.4) Br -CH2-CH2 -Br(c.4) CH3 -CHBr2 (d.4) CH2= CBr2

Q.5Benzylidene chloride is .....(a.5) C6H5CH2Cl (b.5) C6H5CHCl2

(c.5) C6H4ClCH2Cl (d.5) C6H5CCl3Q.6 Which of the following halide is 2°......

(a.6) Isopropyl chloride (b.6) Iso-butyl chloride(c.6) n-propyl chloride (d.6) n-butyl chloride

Q.7 Haloforms are trihalogen derivatives of .....(a.7) Ethane (b.7) Methane (c.7) Propane (d.7) Benzene

Q.8 Benzene hexachloride is ...(a.8) 1, 2, 3, 4, 5, 6-hexachlorocyclohexane(b.8) 1, 1, 1, 6, 6, 6-hexachlorocyclohexane(c.8) 1, 6-phenyl-1, 6-chlorohexane(d.8) 1, 1-phenyl-6, 6-chlorohexane

Q.9 Number of π-bonds present in B.H.C. (Benzene hexa chloride) are ..(a.9) 6 (b.9) Zero (c.9) 7 (d.9) None of these.

Q.10 The general formula for alkyl halides is....(a.10) CnH2n+1X (b.10) CnH2n+2X(c.10) CnHn+1X (d.10) CnH2nX

Q.11 Which of the following is a primary halide....(a.11) Isopropyl iodide (b.11) Secondary butyl iodide(c.11) Tertiary butyl bromide (d.11) Neo hexyl chloride

Q.12 Full name of DDT is(a.12) 1, 1, 1-trichloro-2, 2-bis(p-chlorophenyl) ethane

(b.12) 1, 1-dichloro-2, 2-diphenyl trimethylethane (c.12) 1, 1-dichloro-2, 2-diphenyl trichloroethane (d.12) None of theseQ.13 The compound which contains all the four 1°,2°,3° and 4° carbon atoms is....

(a.13) 2, 3-dimethyl pentane(b.13) 3-chloro-2, 3-dimethylpentane

(c.13) 2, 3, 4-trimethylpentane (d.13) 3, 3-dimethylpentanePreparation of Halogen containing compoundsQ.14 The following reaction is known as.........

(a.14) Kharasch effect (b.14) Darzen’s procedure (c.14) Williamson’s synthesis (d.14) Hunsdiecker synthesis reaction

Q.15 What is the main product of the reaction between 2-methyl propene with HBr.....

(a.15)1-bromo butane(b.15) 1-bromo-2 methyl propane (c.15) 2-bromo butane (d.15) 2-bromo-2 methyl propane

Q.16 Halogenation of alkanes is(a.16) A reductive process (b.16) An oxidative process

(c.16) An isothermal process (d.16) An indothermal process

Q.17 In the above process product A is ......(a.17) Fluorobenzene (b.17) Benzene(c.17) 1, 4-difluorobenzene (d.17) 1, 3-difluorobenzene

Q.18 Silver acetate . The main product of this reaction is..... (a.18) CH3 -Br (b.18) CH3COI (c.18) CH3COOH (d.18) None of these

Q.19 Diazonium salts +Cu2Cl2+ HCl → , the reaction is known as..... (a.19) Chlorination (b.19) Sandmeyer’s reaction(c.19) Perkin reaction (d.19) Substitution reaction

Q.20 When ethyl alcohol (C2H5OH) reacts with thionyl chloride, in the presence of pyridine, the product obtained is......

(a.20) CH3CH2Cl +HCl(b.20) C2H5Cl+HCl+SO2

(c.20) CH3 CH2Cl+ H2O+SO2

(d.20) CH3 CH2Cl+HCl+ SO2

Q.21 Preparation of alkyl halides in laboratory is least preferred by........(a.21) Treatment of alcohols (b.21) Addition of hydrogen halides to alkenes(c.21) Halide exchange(d.21) Direct halogenation of alkanes

Q.22 Which of the following organic compounds will give a mixture of 1- chlorobutane and 2-chlorobutane on chlorination .......

(a.22)

(b.22) (c.22) CH2=CH-CH= CH2

(d.22) CH2=CH -CH2 -CH3

Q.23 The chlorobenzene is generally obtained from a corresponding diazonium salt by reacting it with .......

(a.23) Cu2Cl2 (b.23) CuSO4 (c.23) All of these (d.23)

Q.24 Decreasing order of reactivity of HX in the reaction ROH + HX → RX+ H2O (a.24) HI > HBr > HCl > HF (b.24) HBr > HCl > HI > HF(c.24) HCl > HBr > HI > HF (d.24) HF > HBr > HCl > HI

Q.25 The product of the following reaction : CH2 = CH - CCl3 + HBr (a.25) CH3 - CH(Br)- CCl3 (b.25) CH2(Br) - CH2 - CCl3

(c.25) BrCH2- CHCl – CHCl2 (d.25) None of these.

#2# % of Br

or approx. 75%#3# Gem-dihalides are those in which two halogen atoms are attached

on the same carbon atom.

#6# Isopropyl chloride chlorine atom is attached to 2º carbon atom.

#7# (X = Cl, Br, I) #11# Neohexyl chloride is a primary halide as in it Cl-atom is attached to

a primary carbon.

#12#

13. (b)

#15#

#18# CH3COOAg + Br2 CH3Br + AgBr +CO2

#20# C2H5OH+SOCl2 C2H5Cl+SO2+HCl

TesttwoQ.26 Chlorobenzene is prepared commercially by

(a.26) Raschig process (b.26) Wurtz Fitting reaction(c.26) Friedel-Craft’s reaction (d.26) Grignard reaction

Q.27 In methyl alcohol solution, bromine reacts with ethylene to yield BrCH2CH2OCH3 in addition to 1, 2-dibromoethane because

(a.27) The ion formed initially may react with Br- or CH3OH(b.27) The methyl alcohol solvates the bromine(c.27) The reaction follows Markownikoff's rule(d.27) This is a free-radical mechanism

Q.28 is an example of which of the following types of reactions.......

(a.28) Substitution (b.28) All of these(c.28) Addition (d.28) Rearrangement

Q.29 Which of the following would be produced when acetylene reacts with HCl

(a.29) CH3CH2Cl (b.29) CH3CHCl2

(c.29) CHCl = CHCl (d.29) CH2 = CHClQ.30 R-OH+HX → R-X+H2O

In the above reaction, the reactivity of different alcohols is(a.30) Tertiary > Secondary > Primary(b.30) Tertiary < Secondary < Primary(c.30) Tertiary < Secondary > Primary(d.30) Secondary < Primary < Tertiary

Q.31C6H6 + Cl2 Product. In above reaction product is (a.31) CCl3CHO (b.31) C6H6Cl6

(c.31) C6H12Cl6 (d.31) C6H9Cl2Q.32 Benzene reacts with chlorine to form benzene hexachloride in presence of

(a.32) Nickel (b.32) AlCl3(c.32) Bright sunlight (d.32) All of these

Q.33 The final product obtained by distilling ethyl alcohol with the excess of chlorine and Ca(OH)2 is .......

(a.33) CH3CHO (b.33) CCl3CHO(c.33) CHCl3 (d.33) (CH3)2O

Q.34 When ethyl alcohol and KI reacted in presence of Na2CO3. yellow crystals of...... are formed

(a.34) CHI3 (b.34) CH3I(c.34) CH2I2 (d.34) C2H5I

Q.35 In preparation of CHCl3 from ethanol and bleaching powder, the latter Provides.....

(a.35) Ca(OH)2 (b.35) Cl2(c.35) Both (a) and (b) (d.35) All of these

Q.36 Which one of the following processes does not occur during formation of CHCl3 from C2H5OH and bleaching powder

(a.36) Hydrolysis (b.36) Oxidation(c.36) Reduction (d.36) Chlorination

Q.37 Which of the following is obtained when chloral is boiled with NaOH(a.37) CH3Cl (b.37) CHCl3

(c.37) CCl4 (d.37) CH4

Q.38 Chloroform can be obtained from.....(a.38) Methanol (b.38) Methanal(c.38) Propanol-1 (d.38) Propanol-2

Q.39 Chlorine reacts with ethanol to give..(a.39) Ethyl chloride (b.39) Chloroform(c.39) Acetaldehyde (d.39) Chloral

Q.40 On heating diethyl ether with conc. HI, 2 moles of which of the following is formed....

(a.40) Ethanol (b.40) None of these(c.40) Ethyl iodide (d.40) Methyl iodide

Q.41 Lucas reagent is(a.41) Concentrated HCl + anhydrous ZnCl2

(b.41) Dilute HCl + hydrated ZnCl2 (c.41)Concentrated HNO3 + anhydrous ZnCl2(d.41) Concentrated HCl + anhydrous MgCl2

Q.42 Which compound does not form iodoform with alkali and iodine(a.42) Acetone (b.42) Chloroform(c.42) Diethyl ketone(d.42) Isopropyl alcohol

Q.43 Which compound gives yellow ppt. with iodine and alkali(a.43) 2-hydroxy propane (b.43) Acetophenone(c.43) Methyl acetone (d.43) Acetamide

Q.44 Acetone reacts with I2 in presence of NaOH to form(a.44) C2H5I (b.44) C2H4I2 (c.44) CHI3 (d.44) CH3I

Q.45 Ethanol is converted into ethyl chloride by reacting with (a.45) Cl2 (b.45) SOCl2 (c.45) HCl (d.45) NaCl

Q.46 C6H5Cl prepared by aniline with (a.46) HCl

(b.46) Cu2Cl2 (c.46) Cl2 in presence of anhydrous AlCl3 (d.46) HNO2 and then heated with Cu2Cl2

Q.47 The starting substance for the preparation of CH3I is(a.47) CH3OH (b.47) C2H5OH

(c.47) None of these (d.47) (CH3)2COQ.48 A Grignard's reagent may be made by reacting magnesium with....

(a.48) Methyl amine (b.48) Diethyl ether(c.48) Ethyl iodide (d.48) Ethyl alcohol

Q.49 Which of the following is responsible for iodoform reaction.(a.49) Formalin (b.49) Methanol(c.49) None of these (d.49) Ethanol

Q.50 When a solution of sodium chloride containing ethyl alcohol is electrolysed, it forms......

Answer Key

#27#CH2=CH2+BR2

#28# C3H8 + Cl2 C3H7Cl + HClThis is an example of substitution reaction. Hydrogen atom of alkane is replaced by halogen atom.

#29# CH≡ CH + HCl →CH2=CHCl CH3CHCl2#30# R-OX+HX →R-X+H2O

Reactivity order of alcohols for this reaction 3º > 2º >1º Reactivity order of halogen acids R-I > R-Br > R-Cl

#31#

#32#

#34#

#35#

#36#

yellow ppt.

#37##38# CaOCl2 + H2O →Ca(OH)2 +Cl2

#39# CH3CH2OH+Cl2 →CH3CHO+2HCl

#40#

#42#

#43# #44# CH3COCH3 + 3I2 +4NaOH →

CHI3+3Na+CH3COONa+3H2O

#45#

#46#

#47#

#48#

TestthreeQ.51 Which reagent cannot be used to prepare an alkyl halide from an alcohol

(a.51) HCl + ZnCl2 (b.51) NaCl(c.51) PCl5 (d.51) All of these

Q.52 Ethyl benzoate reacts with PCl5 to give(a.52) C2H5Cl + C6H5COCl+POCl3+HCl(b.52) C2H5Cl + C6H5COCl + POCl3

(c.52) CH3COCl + C6H5COCl + POCl3(d.52) C2H5Cl + C6H5COCH + POCl3

Q.53 On treatment with chlorine in presence of sunlight, toluene gives the product

(a.53) o-chloro toluene (b.53) 2, 5-dichloro toluene (c.53) p-chloro toluene (d.53) Benzyl chloride

Q.54 When chlorine is passed through warm benzene in presence of the sunlight, the product obtained is

(a.54) Benzotrichloride (b.54) Chlorobenzene (c.54) Gammexane (d.54) DDT

Q.55 Which of the following acids adds to propene in the presence of peroxide to give anti-Markownikoff’s product (a.55) HF (b.55) HCl (c.55) HBr (d.55) H2SO4

Q.56 Propene on treatment with HBr gives.......... (a.56) Isopropyl bromide (b.56) Propyl bromide(c.56) 1, 2-dibromoethane (d.56) None of the above

Q.57 The catalyst used in Raschig's process is...(a.57) LiAlH4 (b.57) Copper chloride(c.57) Sunlight (d.57) Ethanol/ Na

Q.58 The compound formed on heating chlorobenzene with chloral in the presence of concentrated sulphuric acid, is........

(a.58) Freon (b.58) DDT(c.58) Gammexene (d.58) Neon

Q.59 Acetone is mixed with bleaching powder to give(a.59) Chloroform (b.59) Acetaldehyde(c.59) Ethanol (d.59) Acetone

Q.60 Which of the following compounds gives trichloromethane on distilling with bleaching powder.........

(a.60) Methanal (b.60) All of these(c.60) Ethanol (d.60) Methanol

Q.61 The product formed on reaction of ethyl alcohol with bleaching powder is

(a.61) CHCl3 (b.61) CCl3CHO(c.61) CH3COCH3 (d.61) CH3CHO

Q.62 Ethylene reacts with bromine to form(a.62) Chloroethane (b.62) Ethylene dibromide(c.62) Cyclohexane (d.62) 1-bromo propane

Q.63 Best method of preparing alkyl chloride is

(a.63) ROH + SOCl2

(b.63) ROH + PCl5

(c.63) ROH + PCl3

(d.63) ROH + HClQ.64 DDT is prepared by reacting chlorobenzene with

(a.64) CCl4 (b.64) CCl3 - CHO(c.64) CHCl3 (d.64) Propane

Q.65 Which compound needs chloral in its synthesis(a.65) D. D. T. (b.65) Gammexane (c.65) Chloroform (d.65) Michler’s Ketone

Q.66 To get DDT, chlorobenzene has to react with which of the following compounds in the presence of concentrated sulphuric acid

(a.66) Trichloroethane (b.66) Dichloroacetone(c.66) Dichloroacetaldehyde (d.66) Trichloroacetaldehyde

Q.67 What will be the product in the following reaction

(a.67)

(b.67)

(c.67)

(d.67)

Q.68 Compounds A is .......

(a.68) (b.68)

(c.68) (d.68)

Q.69 Ethyl bromide can be converted into ethyl alcohol by(a.69) Heating with dilute hydrochloric acid and zinc(b.69) Boiling with an alcoholic solution of KOH(c.69) The action of moist silver oxide(d.69) Refluxing methanol

Q.70. Reaction of ethyl chloride with sodium leads to(a.70) Ethane (b.70) Butane(c.70) n-butane (d.70) n-pentane

Q.71 Treatment of ammonia with excess of ethyl chloride will yield(a.71) Diethyl amine(b.71) Ethane(c.71) Tetraethyl ammonium chloride(d.71) Methyl amine

Q.72 2CHCl3 + O2 2COCl2 + 2HClIn the above reaction, X stands for......(a.72) An oxidant (b.72) A reductant(c.72) Light and air (d.72) None of these

Q.73 Phosgene is the common name for(a.73) CO2 and PH3 (b.73) Phosphoryl chloride(c.73) Carbonyl chloride (d.73) Carbon tetrachloride

Q.74 When chloroform is treated with amine and KOH, we get......(a.74) Rose odour smell(b.74) Sour almond like smell(c.74) Offensive odour(d.74) Sour oil of winter green like smell

Q.75 A mixture of two organic chlorine compounds was treated with sodium metal in ether solution. Isobutane was obtained as a product. The two chlorine compounds are....

(a.75) Methyl chloride and propyl chloride(b.75) Methyl chloride and ethyl chloride(c.75) Isopropyl chloride and methyl chloride(d.75) Isopropyl chloride and ethyl chloride

Answer Key

#56##58# DDT is prepared by heating chlorobenzene and chloral with

concentrated sulphuric acid

#59# Acetone forms chloroform when heated with bleaching powder. CaOCl2+H2O →Ca(OH)2+Cl2 CH3COCH3+3Cl2 →CCl3COCH3+3HCl

#60# Cl2+H2O →2HCl+O

#61# CaOCl2+H2O →Ca(OH)2+Cl2CH3CH2OH+Cl2 →CH3CHO+HCl

#62# When ethylene reacts with bromine, it forms ethylene dibromide.

#63# The chlorination of alcohol by SOCl2 (thionyl chloride) is the best method for the preparation of alkyl halides as in this method all the other product are gaseous and thus halides are obtained on quite

pure state

#64##65# DDT is formed by reaction of chloral with chloro benzene.#67# NBS is a selective brominating reagent since it normally

brominates the ethylenic compounds in the allylic position.

Properties of Halogen containing compounds

#68# As –CCl3 is a m-directing group.

#69# Ag2O+H2O →2AgOH C2H5Br+AgOH →C2H5OH+AgBr

#70#

#71#

If NH3 is in excess, then 1º amine will be the main product, if C2H5Cl is in excess then mixture of 1º,2º,3º and quaternary amine is obtained.

#72# #73# COCl2 carbonyl chloride is commonly called as phosgene. #74# C2H5NH2 + CHCl3+3KOH →

#75#

TestfourQ.76 Alkyl halides can be converted into Grignard reagents by

(a.76) Boiling them with Mg ribbon in alcoholic solution(b.76) Warming them with magnesium powder in dry ether(c.76) Refluxing them with MgCl2 solution(d.76) Warming them with MgCl2

Q.77 Which is not present in Grignard reagent.......(a.77) Methyl group (b.77) Magnesium(c.77) All of these (d.77) –COOH group

Q.78 The reactivity of ethyl chloride is.......(a.78) More or less equal to that of benzyl chloride(b.78) More than that of benzyl chloride(c.78) More or less equal to that of chlorobenzene(d.78) Less than that of chlorobenzene

Q.79 The reactivity of halogen atom is minimum in...(a.79) Propyl chloride (b.79) None of these

(c.79) Isopropyl chloride (d.79) Isopropyl bromideQ.80 Chlorobenzene is

(a.80) Less reactive than benzyl chloride(b.80) More reactive than ethyl bromide(c.80) Nearly as reactive as methyl chloride(d.80) More reactive than isopropyl chloride

Q.81 The reactivities of methyl chloride, propyl chloride and chlorobenzene are in the order

(a.81) Methyl chloride > propyl chloride > chlorobenzene(b.81) Propyl chloride > methyl chloride > chlorobenzene(c.81) Methyl chloride > chlorobenzene > propyl chloride(d.81) Chlorobenzene > propyl chloride > methyl chloride

Q.82 Which of the following compound will make precipitate most readily with AgNO3

(a.82) CCl3CHO (b.82) CCl4(c.82) C6H5CH2Cl (d.82) CHI3

Q.83 Carbylamine is liberated when..... is heated with chloroform and alcoholic potash

(a.83) An aldehyde (b.83) A primary amine(c.83) A secondary amine (d.83) A phenol

Q.84 Salicylic acid can be prepared using Reimer-Tiemann's reaction by treating phenol with

(a.84) Methyl chloride in the presence of anhydrous aluminium chloride

(b.84) Carbon dioxide under pressure in sodium hydroxide solution(c.84) Carbon tetrachloride and concentrated sodium hydroxide(d.84) Sodium nitrite and a few drops of concentrated sulphuric acid

Q.85 Grignard reagent is prepared by the reaction between(a.85) Zinc and alkyl halide(b.85) Magnesium and alkyl halide(c.85) Magnesium and alkane(d.85) Magnesium and aromatic hydrocarbon

Q.86 Reaction of t-butyl bromide with sodium methoxide produces(a.86) Isobutane (b.86) Isobutylene(c.86) Sodium t-butoxide (d.86) t-butyl methyl ether

Q.87 War gas is formed from.......(a.87) PH3 (b.87) C2H2

(c.87) Zinc phosphate (d.87) ChloropicrinQ.88 What happens when CCl4 is treated with AgNO3

(a.88) NO2 will be evolved(b.88) A white ppt. Of AgCl will be formed(c.88) CCl4 will dissolve in AgNO3 (d.88) Nothing will happen

Q.89 If we use pyrene (CCl4) in the Riemer-Tiemann reaction in place of chloroform, the product formed is....

(a.89) Salicylaldehyde (b.89) Phenolphthalein(c.89) Salicylic acid (d.89) Cyclohexanol

Q.90 C6H5CH2Cl + KCN(aq.) →X + Y Compounds X and Y are(a.90) C6H6 + KCl (b.90) C6H5CH2CN + KCl(c.90) C6H5CH3 + KCl (d.90) None of these

Q.91 The bad smelling substance formed by the action of alcoholic caustic potash on chloroform and aniline is......

(a.91) Phenyl isocyanide (b.91) Nitrobenzene(c.91) Phenyl cyanide (d.91) Phenyl isocyanate

Q.92 Ethylidene chloride on treatment with aqueous KOH gives(a.92) Ethylene glycol (b.92) Acetaldehyde(c.92) Formaldehyde (d.92) None

Q.93 Reaction C2H5I + C5H11I + 2Na → C2H5 – C5H11 +2Nal is called(a.93) Hoffmann's reaction(b.93) Dow's reaction(c.93) Wurtz's reaction(d.93) Riemer-Tiemann's reaction

Q.94 In presence of AlCl3, benzene and n-propyl bromide react in Friedal- Craft's reaction to form

(a.94) n-propyl benzene(b.94) 1, 2-dinormal propyl benzene(c.94) 1, 4-dinormal propyl benzene(d.94) Isopropyl benzene

Q.95 The dehydrobromination of 2-bromobutane gives CH3CH = CHCH3. The product is......

(a.95) Hofmann product(b.95) Saytzeff product(c.95) Hoffmann-Saytzeff product(d.95) Markownikoff product

Q.96 Ethylene difluoride on hydrolysis gives (a.96) Glycol (b.96) Fluoroethanol(c.96) Difluoroethanol (d.96) Freon

Q.97 Benzyl chloride when oxidised by pb(NO3)2 gives(a.97) Benzoic acid (b.97) Benzaldehyde(c.97) Benzene (d.97) None

Q.98 Which of the following statements about chloroform is false(a.98) It is a colourless, sweet-smelling liquid(b.98) It is almost insoluble in water(c.98) It is highly inflammable(d.98) It can be used as an inhalational anaesthetic agent

Q.99 CCl4 cannot give precipitate with AgNO3 due to(a.99) Formation of complex with AgNO3

(b.99) Evolution of Cl2 gas(c.99) Chloride ion is not formed(d.99) AgNO3 does not give silver ion

Q.100 On heating CHCl3 with aq. NaOH, the product is......(a.100) CH3COONa (b.100) HCOONa(c.100) Sodium oxalate (d.100) CH3OH

Answer Key

#76#

#78#

#80# Chlorobenzene is less reactive than benzyl

chloride

In chlorobenzene the lone pairs present on Cl atom get involved in resonance with π electrons of benzene due to which C-Cl bond acquires double bond character Hence, reactivity decreases.

#81# CH3-Cl> CH3-CH2-Cl>

#82# CHI3 gives a yellow ppt. of AgI.

#84# + CCl4+4NaOH→4NaCl+2H2O

#85# (X=Cl,Br,I)

#86#

CH3ONa →CH3O-+Na+

methoxide ion (CH3O-) is a strong base, therefore it abstract proton from 3º alkyl halide and favours elimination reaction.

#87# #88# CCl4 +AgNO3 → No reaction CCl4 is a covalent compound. Therefore does not provide Cl- ions.

#89#

#90# C6H5 - CH2 – Cl + KCN(aq) → C6H5 - CH2 – C ≡ N + KCl

#91#

#92#

#94#

#95#

#96#

#97##99# CCl4 is a covalent compound, Hence it does not give Cl- ion in

solution. CCl4 + AgNO3→No reaction

#100#

TestfiveQ.101 Ethyl bromide reacts with lead-sodium alloy to form

(a.101) Tetraethyl lead (b.101) Tetraethyl bromide(c.101) Both (a) and (b) (d.101) None of the above

Q.102 Iodoform heated with Ag powder to form (a.102) Acetylene (b.102) Ethylene(c.102) Methane (d.102) Ethane

Q.103 Ethyl bromide reacts with silver nitrite to form (a.103) Nitroethane(b.103) Nitroethane and ethyl nitrite(c.103) Ethyl nitrite(d.103) Ethane

Q.104 Which of the following reactions leads to the formation of chloritone(a.104) CHCl3 + CH3COCH3 (b.104) CCl4 + Acetone(c.104) CHCl3 + KOH (d.104) CHCl3 + HNO3

Q.105 CH3 – CH2 - CH2Br + KOH (alc.) →Product. Product in above reaction is...... (a.105) CH3 – CH = CH2 (b.105) CH3 –CH2 –CH3

(c.105) (a) and (b) both (d.105) None of theseQ.106 A + CCl4 + KOH →Salicylic acid

‘A’ in above reaction is......

(a.106) (b.106)

(c.106) (d.106)Q.107 Identify X and Y in the following sequence

C2H5Br product C3H7NH2 (a.107) X = KCN, Y = LiAlH4

(b.107) X = KCN, Y = H3O+

(c.107) X = CH3Cl, Y = AlCl3 / HCl(d.107) X = CH3NH2, Y = HNO2

Q.108 1-chlorobutane reacts with alcoholic KOH to form(a.108) 1-butene (b.108) 2-butane(c.108) 1-butanol (d.108) 2-butanol

Q.109 Which of the following reactions gives H2C = C = C = CH2

(a.109) CH2Br-CBr= CH2

(b.109) HC ≡ C – CH2 -COOH

(c.109) CH2Br – C ≡ C- CH2Br

(d.109) 2CH2 = CH – CH2IQ.110 When ethyl amine is heated with chloroform and alcoholic KOH, a compound with offensive smell is obtained. This compound is......

(a.110) A secondary amine (b.110) An isocyanide(c.110) A cyanide (d.110) An acid

Q.111 Chlorobenzene on fusing with solid NaOH gives(a.111) Benzene (b.111) Benzoic acid(c.111) Phenol (d.111) Benzene chloride

Q.112 DDT can be prepared by reacting chlorobenzene (in the presence of conc.H2SO4) with

(a.112) Cl2 in ultraviolet light (b.112) Chloroform(c.112) Trichloroacetone (d.112) Chloral hydrate

Q.113 When phenol reacts with CHCl3 and KOH, the product obtained would be (a.113) Salicylaldehyde (b.113) p-hydroxy benzaldehyde

(c.113) Both (a) and (b) (d.113) ChloretoneQ.114 Ethyl chloride on heating with silver cyanide forms a compound X. The functional isomer of X is......

(a.114) C2H5NC (b.114) C2H5CN (c.114) H3C – NH – CH3 (d.114) C2H5NH2

Q.115 Which of the following statements is incorrect(a.115) C2H5Br reacts with alco. KOH to form C2H5OH

(b.115) C2H5Br when treated with metallic sodium gives ethane

(c.115) C2H5Br when treated with sodium ethoxide forms diethyl ether

(d.115) Both (a) and (b)Q.116 When chloroform is exposed to air and sunlight, it gives

(a.116) Carbon tetrachloride (b.116) Carbonyl chloride(c.116) Mustard gas (d.116) Lewsite

Q.117 An organic halide is shaken with aqueous NaOH followed by the addition of dil. HNO3 and silver nitrate solution gave white ppt. The substance can be

(a.117) C6H4(CH3)Br (b.117) C6H5CH2Cl(c.117) C6H5Cl (d.117) None of these

Q.118 A compound A has a molecular formula C2Cl3OH. It reduces Fehling solution and on oxidation gives a monocarboxylic acid (B). A is obtained by action of chlorine on ethyl alcohol. A is......

(a.118) Chloral (b.118) CHCl3(c.118) CH3Cl (d.118) Chloroacetic acid

Q.119 Following equation illustrates

C6H5Cl + 2NaOH C6H5ONa + NaCl + H2O(a.119) Dow's process (b.119) Kolbe's process(c.119) Carbylamine test (d.119) Haloform reaction

Q.120 One of the following that cannot undergo dehydro-halogenation is...... (a.120) Iso-propyl bromide (b.120) Ethanol

(c.120) Ethyl bromide (d.120) None of theseQ.121 A compound X on reaction with chloroform and NaOH gives a compound with a very unpleasant odour. X is......

(a.121) C6H5CONH2 (b.121) C6H5NH2

(c.121) C6H5CH2NHCH3 (d.121) C6H5NHCH3

Q.122In the above reaction product is......(a.122) C6H5OC2H5 (b.122) C2H5OC2H5

(c.122) C6H5OC6H5 (d.122) C6H5I

Q.123 C2H5Cl + KCN → X Y. 'X' and 'Y' are(a.123) C2H6 and C2H5CN(b.123) C2H5CN and C2H6

(c.123) C2H5CN and C2H5CH2NH2 (d.123) C2H5CN and C2H5COOH

Q.124 Iodoform is formed on warming I2 and NaOH with(a.124) C2H5OH (b.124) CH3OH(c.124) HCOOH (d.124) C6H6

Q.125 Which of the following reacts with phenol to give salicylaldehyde after hydrolysis

(a.125) Dichloromethane (b.125) Trichloromethane

(c.125) Methyl chloride (d.125) None of these

Answer Key

#101#

#102#

#103#

Ag-O-N=O is a covalent compound. Therefore, attack of nucleophile occurs through Nitrogen atom. Hence, nitroethane is formed.

#107# C2H5Br C2H5CN C2H5CH2NH2(C3H7NH2)

X=KCN,Y=LiAlH4

#108# CH3CH2CH2CH2 – Cl + KOH(alc.)→

#109# CH2=C=C=CH2

#110# +3KCl + 3H2O

#111#

#113#

#114#The functional isomer of ethyl isocyanide is ethyl cyanide C2H5-C≡N.

#115# C2H5Br+alc.KOH→ C2H4+H2O+KBr

#116#

#117# White ppt of AgCl are obtained.

#118# It means –CHO group is present.

It means only one –CHO group is present.C2H5OH+Cl2→CH3CHO+2HCl

#120# Ethanol cannot undergo dehydrohalogenation.

#121#

#122#

#123# C2H5Cl+KCN

#124#

#125#

TestsixQ.126 Dehydrohalogenation in monohaloalkanes produces

(a.126) A single bond (b.126) A double bond(c.126) A triple bond (d.126) Fragmentation

Q.127 When chloroform is treated with conc. HNO3 it gives(a.127) CHCl2NO2 (b.127) CCl3NO2

(c.127) CHCl2HNO3 (d.127) None of theseQ.128 A sample of chloroform being used as anaesthetic is tested by

(a.128) Fehling solution(b.128) AgNO3 solution

(c.128) AgNO3 solution after boiling with alcoholic KOH solution (d.128) Both (b) and (c)Q.129 Dehydrohalogenation of an alkyl halide is......

(a.129) An addition reaction (b.129) A substitution reaction(c.129) An elimination reaction (d.129) An oxidation reaction

Q.130 Reaction of aqueous sodium hydroxide on (i) ethyl bromide and (ii) chlorobenzene gives

(a.130) (i) Ethene and (ii) o-chlorophenol(b.130) (i) Ethyl alcohol and (ii) o-chlorophenol(c.130) (i) Ethyl alcohol and (ii) phenol(d.130) (i) Ethyl alcohol and (ii) no reaction

Q.131 2-bromopentane is heated with potassium ethoxide in ethanol. The major product obtained is

(a.131) Pentene-1 (b.131) cis pentene-2(c.131) trans pentene-2 (d.131) 2-ethoxypentane

Q.132 What is the product formed in the following reaction

C6H5OH + CCl4 (a.132) p-hydroxybenzoic acid (b.132) o-hydroxybenzoic

acid(c.132) Benzaldehyde (d.132) Salicylaldehyde

Q.133 When chloroform is treated with excess oxygen it forms (a.133) COCl2 + HCl (b.133) COCl2 + Cl2 + H2

(c.133) COCl2 + Cl2 +H2O (d.133) No product will be formed

Q.134 Which isomer of cyclohexane hexachloride is a very strong insecticide

(a.134) α (b.134) β (c.134) γ (d.134) X

Q.135 Haloalkane in the presence of alcoholic KOH undergoes (a.135) Elimination (b.135) Polymerisation (c.135) Dimerisation (d.135) Substitution

Q.136 The set of compounds in which the reactivity of halogen atom in the ascending order is......

(a.136) Vinyl chloride, chlorethane, chlorobenzene (b.136) Vinyl chloride, chlorobenzene, chloroethane (c.136) Chloroethane, chlorobenzene, vinyl chloride (d.136) Chlorobenzene, vinyl chloride chloroethane

Q.137 Alkyl halides react with Mg in dry ether to form (a.137) Magnesium halide (b.137) Grignard’s reagent

(c.137) Alkene (d.137) AlkyneQ.138 In the following sequence of reactions

The product (C) is...... (a.138) Propan – 2 - ol (b.138) Propan – l – ol

(c.138) Propyne (d.138) PropeneQ.139 Alkyl halide on heating with alc. NH3 in a sealed tube results…

(a.139) 1° amine (b.139) 2° amine

(c.139) 3° amine (d.139) All of theseQ.140 When CH3CH2CHCl2 is treated with NaNH2, the product formed is......

(a.140) CH3-CH = CH2 (b.140) CH3 - C ≡ CH (c.140) CH3CH2CH(NH2)(Cl) (d.140) CH3CH2C (NH2)2

Q.141 By heating a mixture of CHCl3 with silver powder, the compound formed is......

(a.141) Acetylene (b.141) Silver acetate (c.141) Propanol (d.141) None of these

Q.142 Chloropicrin is...... (a.142) Trichloro acetaldehyde (b.142) Nitrochloroform(c.142) 2,4,6-trinitro phenol (d.142) None of these

Q.143 Which of the following are correct statements about C2H5Br (a.143) It reacts with metallic Na to give ethane (b.143) It gives nitroethane on heating with aqueous ethanolic solution of AgNO2

(c.143) It forms ethylacetate on heating with silver acetate (d.143) Both (b) and (c)

Q.144 Aryl halide is less reactive than alkyl halide towards nucleophilic substitution because

(a.144) Less stable carbonium ion (b.144) Due to large C –Cl bond energy (c.144) Inductive effect (d.144) Resonance stabilization and sp2- hybridisation of C

attached to halide

Q.145 Methyl chloride reacts with silver acetate to yield (a.145) Acetaldehyde (b.145) Acetyl chloride (c.145) Methyl acetate (d.145) Acetic acid

Q.146 Chloroform for anesthetic purposes is tested for its purity with the reagent

(a.146) Silver nitrate (b.146) Lead nitrate (c.146) Ammoniacal Cu2Cl2 (d.146) Lead nitrate

Q.147 2, 6 - Dimethylheptane on monochlorination produces……. derivatives

(a.147) 5 (b.147) 6 (c.147) 1 (d.147) 4

Q.148 The less reactivity of chlorine atom in CH2 = CH - Cl is due to (a.148) Inductive effect (b.148) Resonance stabilization (c.148) Electromeric effect (d.148) All of these

Q.149 CH3-CH2-Br CH3CH2CN X

In this reaction, product X is......(a.149) Acetic acid (b.149) Propionic acid (c.149) Butyric acid (d.149) Hydrochloric acid

Q.150 In alkaline hydrolysis of a tertiary alkyl halide by aqueous alkali if concentration of alkali is doubled, then the reaction

(a.150) Will be doubled (b.150) Will be halved (c.150) Will remain constant (d.150) Can’t say

Answer Key

#126#

#127# #128# Before using the sample of chloroform as an anaesthetic, it is

tested by treating with aq. solution of AgNO3. A pure sample does not give ppt with aq. AgNO3.

#129# Alkyl halide gives alkene on elimination, reaction takes place in presence of alc. KOH.

CH3CH2Br+Alc.KOH→CH2=CH2+KBr+H2OThere are two types of elimination reactions.(a) E1→ Unimolecular elimination(b) E2→ Bimolecular elimination

#130# (i) Ethyl alcohol (ii) Phenol

#131#

When alkyl halide reacts with alc. KOH then it favours elimination reaction (Dehydrohalogenation). Since, trans pentene-2 is more symmetrical than cis isomers. Hence, it is main product.

#133##137# Alkyl halide reacts with Mg in presence of dry ether to give alkyl

magnesium halide which is also called as Grignard reagent. This reaction is also called as Grignard’s reaction.

HBr

#138#

#143#

#146# If CHCl3 sample contains phosgene (COCl2) then it will give a

white ppt. When treated with cold AgNO3.

#147# Because has four methyl groups on the corner so it can produce for derivatives

TestsevenQ.151 AgNO3 does not give precipitate with CHCl3 because

(a.151) CHCl3 does not ionise in water (b.151) AgNO3 does not reacts with CHCl3 (c.151) CHCl3 is chemically inert (d.151) None of these

Q.152 The reaction between chlorobenzene and chloral in the presence of concentrated sulphuric acid produces

(a.152) Gammexane (b.152) p,p-dichloro diphenyl trichloro ethane (c.152) Chloropicrin (d.152) Benzene hexachloride

Q.153 False statement is...... (a.153) Vinyl chloride is more reactive than allyl chloride (b.153) Br- is a good nucleophile as compared to I-

(c.153) Chloroform is heavier than water (d.153) Both (a) and (b)

Q.154 Chloroform is slowly oxidise by air in presence of light to form (a.154) Formyl chloride (b.154) Phosgene (c.154) Trichloroacetic acid (d.154) Formic acid

Q.155 Alcoholic potash is used to bring about (a.155) Dehydrogenation (b.155) Dehydration (c.155) Dehydrohalogenation (d.155) Dehalogenation

Q.156 Vinyl chloride reacts with HCl to form (a.156) 1, 1- dichloro ethane (b.156) 1, 2- dichloro ethane (c.156) Tetrachloro ethylene (d.156) Mixture of 1, 2 and 1, 1 – dichloro ethane

Q.157 R-X + NaOH → ROH + NaX The above reaction is classified as

(a.157) Nucleophilic substitution (b.157) Electrophilic substitution

(c.157) Reduction (d.157) OxidationQ.158 Reduction of acetyl chloride with H2 in presence of Pd gives

(a.158) CH3COCH3 (b.158) C2H5OH (c.158) CH3COOH (d.158) CH3CHO

Q.159 When methyl bromide is heated with Zn it gives(a.159) CH4 (b.159) C2H6

(c.159) C2H4 (d.159) CH3OHQ.160 Phenol reacts with CHCl3 and NaOH (at 340 K) to give

(a.160) o-chlorophenol (b.160) Salicylaldehyde(c.160) Benzaldehyde (d.160) Chlorobenzene

Q.161 Iodoform on heating with KOH gives (a.161) CH3CHO (b.161) CH3COOK (c.161) HCOOK (d.161) HCHO

Q.162 Which reaction is correct in the conversion of chloroform to acetylene (a.162) CHCl3 + AgNO3 (b.162) CHCl3 + O2

(c.162) CHCl3 + HNO3 (d.162) CHCl3 + AgQ.163 Which of the following gases are poisonous

(a.163) CHCl3 (b.163) CO2

(c.163) None of these (d.163) COQ.164 Which of the following alkyl halide is used as a methylating agent

(a.164) CH3I (b.164) C2H5Br (c.164) C2H5Cl (d.164) C6H5Cl

Q.165 C6H6Cl6 , on treatment with alcoholic KOH, yields (a.165) C6H6 (b.165) C6H3Cl3

(c.165) (C6H6)OH (d.165) C6H6Cl4Q.166 When ethyl iodide is heated with silver nitrate, the product obtained is

(a.166) C2H5Ag (b.166) Ag-O-NO2

(c.166) C2H5O-NO2 (d.166) C2H5I-NO2

Q.167 CHCl3 and HF lead to the formation of a compound of fluorine of molecular weight 70. The compound is

(a.167) Fluoroform (b.167) Fluorine monoxide (c.167) Fluorine dioxide (d.167) Fluromethanol

Q.168 Chloroform with zinc dust in water gives (a.168) CH4 (b.168) Chloropicrin (c.168) CCl4 (d.168) CH2Cl2

Q.169 Which of the following is used as a catalyst for preparing Grignard reagent

(a.169) Iron powder (b.169) Iodine powder(c.169) Activated charcoal (d.169) Manganese dioxide

Q.170 For a given alkyl group the densities of the halides follow the order(a.170) RI < RBr < RCl (b.170) RI < RCl < RBr(c.170) RBr < RI < RCl (d.170) RCl < RBr < RI

Q.171 Which halide will be least reactive in respect to hydrolysis (a.171) Vinyl chloride (b.171) Allyl chloride (c.171) Ethyl chloride (d.171) t-Butyl chloride

Q.172 In nucleophilic aliphatic substitution, the nucleophiles are generally (a.172) Acids (b.172) Bases (c.172) Salts (d.172) Neutral molecules

Q.173 Which one of the following compounds does not react with bromine (a.173) Ethylamine (b.173) Propene (c.173) Phenol (d.173) Chloroform

Q.174 Allyl chloride on dehydro chlorination gives (a.174) Propadiene (b.174) Propylene (c.174) Acetylchloride (d.174) Acetone

Q.175 Toluene reacts with excess of Cl2 in presence of sunlight to give a product which on hydrolysis followed by reaction with NaOH gives

(a.175) (b.175)

(c.175) (d.175) None of these

TesteightQ.176 An alkyl bromide produces a single alkene when it reacts with sodium ethoxide and ethanol. This alkene undergoes hydrogenation and produces 2-methyl butane. What is the identity of the alkyl bromide

(a.176) 1-bromo-2, 2-dimethylpropane (b.176) 1-bromobutane (c.176) 1-bromo-2-methylbutane (d.176) 2-bromo-2-methylbutane (e.176) 2-bromopentane

Q.177 On treating a mixture of two alkyl halides with sodium metal in dry ether, 2-methyl propane was obtained. The alkyl halides are

(a.177) 2-chloropropane and chloromethane (b.177) 2-chloropropane and chloroethane (c.177) Chloromethane and chloroethane (d.177) Chloromethane and 1-chloropropane

Q.178 In which case formation of butane nitrile is possible (a.178) C3H7Br + KCN (b.178) C4H9Br + KCN (c.178) C3H7OH + KCN (d.178) C4H9OH + KCN

Q.179 The reaction of an aeromatic halogen compound with an alkyl halides in presence of sodium and ether is called

(a.179) Wurtz reaction (b.179) Sandmeyer’s reaction (c.179) Wurtz-fittig reaction (d.179) Kolbe reaction

Q.180 The compound added to prevent chloroform to form phosgene gas is......

(a.180) C2H5OH (b.180) CH3COOH (c.180) CH3COCH3 (d.180) CH3OH

Q.181 Among the following, the one which reacts most readily with ethanol is......

(a.181) p-nitrobenzyl bromide (b.181) p-chlorobenzyl bromide (c.181) p-methoxybenzyl bromide (d.181) p-methylbenzyl bromide

Q.182 Chloropicrin is obtained by the reaction of (a.182) Chlorine on picric acid (b.182) Nitric acid on chloroform (c.182) Steam on carbon tetrachloride (d.182) Nitric acid on chlorobenzene

Q.183 In Wurtz reaction alkyl halide react with (a.183) Sodium in ether (b.183) Sodium in dry ether (c.183) Sodium only (d.183) Alkyl halide in ether

Q.184 Chloroform, when kept open, is oxidised to (a.184) CO2 (b.184) COCl2

(c.184) CO2, Cl2 (d.184) None of theseQ.185 Chloroform reacts with concentrated HNO3 to give

(a.185) Water gas (b.185) Tear gas (c.185) Laughing gas (d.185) Producer gas

Q.186 When ethyl chloride and alcoholic KOH are heated, the compound obtained is

(a.186) C2H4 (b.186) C2H2

(c.186) C6H6 (d.186) C2H6

Q.187 Chloroform, on warming with Ag powder, gives (a.187) C2H6 (b.187) C3H8

(c.187) C2H4 (d.187) C2H2

Q.188 When alkyl halide is heated with dry Ag2O, it produces (a.188) Ester (b.188) Ether (c.188) Ketone (d.188) Alcohol

Q.189 Reaction of alkyl halides with aromatic compounds in presence of anhydrous AlCl3 is known as

(a.189) Friedal-Craft reaction (b.189) Hofmann degradation (c.189) Kolbe’s synthesis (d.189) Beckmann rearrangement

Q.190 Two percent of ethanol is added during the oxidation of chloroform to stop the formation of carbonyl chloride. In this reaction ethanol acts as

(a.190) Auto catalyst (b.190) Negative catalyst (c.190) Positive catalyst (d.190) None of these

Q.191 When benzene is heated with chlorine in the presence of sunlight, it forms

(a.191) B.H.C. (b.191) Cyclopropane (c.191) p-dichlorobenzene (d.191) None of these

Q.192 Ethylene di bromide on heating with metallic sodium in ether solution

yields(a.192) Ethene (b.192) Ethyne

(c.192) 2-butene (d.192) 1-buteneQ.193 The reaction,CH3Br + Na→ Product, is called

(a.193) Perkin reaction (b.193) Levit reaction (c.193) Wurtz reaction (d.193) Aldol condensation

Q.194 At normal temperature iodoform is (a.194) Thick viscous liquid (b.194) Gas (c.194) Volatile liquid (d.194) Solid

Q.195 Which of the following statements about benzyl chloride is incorrect(a.195) It is less reactive than alkyl halides

(b.195) It can be oxidised to benzaldehyde by boiling with copper nitrate solution

(c.195) It is a lachrymatory liquid and answers Beilstein’s test (d.195) It gives a white precipitate with alcoholic silver nitrate

Q.196 Ethylene dichloride and ethylidine chloride are isomeric compounds. The false statement about these isomers is that they

(a.196) React with alcoholic potash and give the same product(b.196) Are position isomers(c.196) Contain the same percentage of chlorine(d.196) Are both hydrolysed to the same product

Q.197 An alkyl bromide (X) reacts with Na to form 4, 5-diethyloctane. Compound X is......

(a.197) CH3(CH2)3Br (b.197) CH3(CH2)5Br(c.197) CH3(CH2)3CH.Br.CH3

(d.197) CH3(CH2)2CH.Br.CH2CH3

Q.198 In the following reaction X is...... CH3NH2 + X+ KOH → CH3NC ( highly offensive odour)

(a.198) CH2Cl2 (b.198) CHCl3

(c.198) CH3Cl (d.198) CCl4Q.199 Which metal is used in Wurtz synthesis......

(a.199) Ba (b.199) Al(c.199) Na (d.199) Fe

Q.200 Which of the following is boiled with ethyl chloride to form ethyl alcohol

(a.200) Alcoholic KOH (b.200) Aqueous KOH (c.200) H2O (d.200) H2O2

Testnine

Q.201 Why is chloroform put into dark coloured bottles (a.201) To prevent evaporation (b.201) To prevent from moisture (c.201) To prevent it from oxidation to form phosgene (d.201) To prevent its reaction with glass

Q.202 DDT is......

(a.202) A solid (b.202) A liquid (c.202) A gas (d.202) A solutionQ.203 Bottles containing C6H5I and C6H5CH2I lost their original labels. They were labelled A and B for testing. A and B were separately taken in test tubes and boiled with NaOH solution. The end solution in each tube was made acidic with dilute HNO3 and then some AgNO3 solution was added. Substance B give a yellow precipitate. Which one of the following statements is true for this experiment

(a.203) A was C6H5I (b.203) A was C6H5CH2I (c.203) B was C6H5I (d.203) Addition of HNO3was unnecessary

Q.204 Which of the following statements is incorrect regarding benzyl chloride

(a.204) It gives white precipitate with alcoholic AgNO3 (b.204) It is an aromatic compound with substitution in the side

chain (c.204) It undergoes nucleophilic substitution reaction (d.204) It is less reactive than vinyl chloride

Q.205 Alkyl halide can be converted into alkene by (a.205) Nucleophilic substitution reaction (b.205) Elimination reaction

(c.205) Both nucleophilic substitution and elimination reaction (d.205) Rearrangement

Q.206 The major product formed in the following reaction is......

(a.206)

(b.206)

(c.206)

(d.206) Q.207 The major product obtained on treatment of CH3CH2CH(F)CH3 with CH3O- / CH3OH is......

(a.207) CH3CH2CH(OCH3)CH3

(b.207) CH3CH=CHCH3

(c.207) CH3CH2CH = CH2

(d.207) CH3CH2CH2CH2OCH3

Q.208 When phenyl magnesium bromide reacts with tbutanol, the product would be

(a.208) Benzene (b.208) Phenol(c.208) tbutyl benzene (d.208) tbutyl phenyl ether

Q.209 Alkyl halides react with dialkyl copper reagents to give (a.209) Alkenes (b.209) Alkyl copper halides (c.209) Alkanes (d.209) Alkenyl halides

Q.210 Which of the following is liquid at room temperature (a.210) CH3I (b.210) CH3Br (c.210) C2H5Cl (d.210) CH3F

Q.211 Which of the following haloalkanes is most reactive(a.211) 1-chloropropane (b.211) 1-bromopropane(c.211) 2-chloropropane (d.211) 2-bromopropane

Q.212 Grignard reagent adds to (a.212) > C = O (b.212) –C ≡ N(c.212) > C =S (d.212) All of the above

Q.213 Analyse the following reaction and identify the nature of A and B

(a.213) Both A and B are

(b.213) Both A and B are

(c.213) A is & B is

(d.213) A is & B is

(e.213) A is & B isQ.214 Which of these can be used as moth repellant

(a.214) Benzene hexachloride (b.214) Benzal chloride(c.214) Hexachloroethane (d.214) Tetrachloroethane

Q.215 Which one of the following is the correct formula of dichlorodiphenyl

trichloroethane

(a.215)

(b.215)

(c.215)

(d.215)

Q.216 The compound is......(a.216) Chloretone (b.216) Chloroquin(c.216) Chloropicrin (d.216) Chloropropyl chloride

Q.217 Depletion of ozone layer is caused by (a.217) Freon (b.217) Alkane (c.217) Gringard reagent (d.217) All of these

Q.218 Which of the following is Teflon

(a.218) [-CF2 – CF2-]n (b.218) CF2 = CF2

(c.218) CF ≡ CF (d.218) None of theseQ.219 Statement “Ozone in atmosphere is decreased by chloro-fluoro- carbon (Cl2F2C)”

(a.219) Is true (b.219) Is false

(c.219) Only in presence of CO2

(d.219) Only in absence of CO2

Q.220 CFxCly[where x + y = 4]. These compounds are not used because (a.220) These are fluoro carbons (b.220) These are difficult to synthesise (c.220) They deplete ozone layer (d.220) None of the these

Q.221 The molecular formula of DDT has(a.221) 5 chlorine atoms (b.221) 4 chlorine atoms(c.221) 3 chlorine atoms (d.221) 2 chlorine atoms

Q.222 What is the reagent used for testing fluoride ion in water (a.222) Alizarin - S (b.222) Quinalizarin (c.222) Phenolphthalein (d.222) Benzene

Q.223 Chloropicrin is used as (a.223) Solvent (b.223) Anaesthetic (c.223) Perfume (d.223) Tear gas

Q.224 Which is used in the manufacture of plastic (a.224) CH2 = CHCl (b.224) CH ≡ CH

(c.224) CH2 = CH – CH2I (d.224) CCl4Q.225 Freon (dichlorodifluoro methane) is used

(a.225) As local anaesthetic (b.225) For dissolving impurities in metallurgical process (c.225) In refrigerator (d.225) In printing industry

TesttenQ.226 Which of the following is known as freon which is used as a Refrigerant

(a.226) CCl2F2 (b.226) CHCl3 (c.226) CH2F2 (d.226) CF4

Q.227 Benzene hexachloride (BHC) is used as (a.227) Dye (b.227) Antimalerial drug (c.227) Antibiotic (d.227) Insecticide

Q.228 Which plastic is obtained from CHCl3 as follows

(a.228) Bakelite (b.228) Teflon(c.228) Polythene (d.228) Perspex

Q.229 The above structural formula refers to

(a.229) BHC (b.229) DNA(c.229) DDT (d.229) RNA

Q.230 The commercial uses of DDT and benzene hexachloride are(a.230) DDT is a herbicide, benzene hexachloride is a fungicide(b.230) Both are insecticides(c.230) Both are herbicides

(d.230) DDT is a fungicide and benzene hexachloride is a herbicideQ.231 Which of the following is used in fire extinguishers

(a.231) CH4 (b.231) CHCl3(c.231) CH2Cl2 (d.231) CCl4

Q.232 Iodoform can be used as(a.232) Anaesthetic (b.232) Antiseptic(c.232) Analgesic (d.232) Antifebrin

Q.233 Which of the following is an anaesthetic(a.233) C2H4 (b.233) CHCl3

(c.233) CH3Cl (d.233) C2H5OHQ.234 An important insecticide is obtained by the action of chloral on chlorobenzene. It is

(a.234) BHC (b.234) Gammexene(c.234) DDT (d.234) Lindane

Q.235 In fire extinguisher, pyrene is(a.235) CO2 (b.235) CCl4

(c.235) CS2 (d.235) CHCl3Q.236 B.H.C. is used as

(a.236) Insecticide (b.236) Pesticide (c.236) Herbicide (d.236) Weedicide

Q.237 The use of the product obtained as a result of reaction between acetone and chloroform is......

(a.237) Hypnotic (b.237) Antiseptic (c.237) Germicidal (d.237) Anaesthetic

Q.238 Use of chlorofluoro carbons is not encouraged because (a.238) They are harmful to the eyes of people that use it (b.238) They damage the refrigerators and air conditioners

(c.238) They eat away the ozone in the atmosphere(d.238) They destroy the oxygen layer

Q.239 Among the following, the molecule with the highest dipole moment is...... (a.239) CH3Cl (b.239) CH2Cl2 (c.239) CHCl3 (d.239) CCl4Q.240 When CHCl3 is boiled with NaOH, It gives

(a.240) Formic acid (b.240) Trihydroxy methane (c.240) Acetylene (d.240) Sodium formate

Q.241 The hybridization state of carbon atoms in the product formed by the reaction of ethyl chloride with aqueous potassium hydroxide is......

(a.241) sp (b.241) sp2 (c.241) sp3 (d.241) sp3dQ.242 Which of the following compounds does not undergo nucleophilic substitution reactions

(a.242) Vinyl chloride (b.242) Ethyl bromide(c.242) Benzyl chloride (d.242) Isopropyl chloride

Q.243 Replacement of Cl of chlorobenzene to give phenol requires drastic

conditions but chlorine of 2, 4-dinitrochlorobenzene is readily replaced because

(a.243) NO2 make ring electron rich at ortho and para(b.243) NO2withdraws e- from meta position(c.243) denotes e- at meta position(d.243) NO2 withdraws e- from ortho/para positions

Q.244 Among the following one with the highest percentage of chlorine is...... (a.244) Chloral (b.244) Pyrene

(c.244) PVC (d.244) GammexeneQ.245 In which alkyl halide,SN2 mechanism is favoured maximum

(a.245) CH3Cl (b.245) CH3CH2Cl(c.245) (CH3)2CHCl (d.245) (CH3)3C-Cl

Q.246 Which conformation of C6H6Cl6 is most powerful insecticide(a.246) aaeeee (b.246) aaaeee(c.246) aaaaee (d.246) aaaaaa

Q.247 The odd decomposition of carbon chlorine bond form (a.247) Two free ions (b.247) Two-carbanium ion (c.247) Two carbanion (d.247) A cation and an anion

Q.248 A new carbon-carbon bond formation is possible in(a.248) Cannizzaro reaction (b.248) Friedel-Craft's alkylation(c.248) Reimer-Tiemann reaction (d.248) Both (b) and (c)

Q.249 An isomer of C3H6Cl2 on boiling with aqueous KOH gives acetone. Hence, the isomer is

(a.249) 2, 2-dichloropropane(b.249) 1, 2-dichloropropane (c.249) 1, 1-dichloropropane (d.249) 1, 3-dichloropropane

Q.250 Which of the following is the example of SN2 reaction

(a.250)

(b.250)

(c.250)

(d

.250)

TestelevenQ.251 Wurtz reaction of methyl iodide yields an organic compound X. Which one of the following reactions also yields X

(a.251) C2H5Cl + Mg

(b.251) C2H5Cl + LiAlH4

(c.251) C2H5Cl + C2H5ONa

(d.251) CHCl3Q.252 Ethyl orthoformate is formed by heating with sodium ethoxide

(a.252) CHCl3 (b.252) C2H5OH(c.252) HCOOH (d.252) CH3CHO

Q.253 1 , 2 di-bromo cyclohexane on dehydro halogenation gives

(a.253) (b.253)

(c.253) (d.253) None of theseQ.254 In which one of the following conversions phosphorus pentachloride

is used as a reagent (a.254) H2C = CH2 → CH3CH2Cl (b.254) H3C – O – CH3 → CH3Cl (c.254) CH3CH2OH →CH3CH2Cl (d.254) Both (b) and (c)

Q.255 When but –3-en -2- ol reacts with aq. HBr, the product formed is...... (a.255) 3 - bromobut - 1- ene (b.255) 1 - bromobut - 2- ene (c.255) A mixture of both a and b (d.255) 2 - bromobut - 2 - ene

Q.256 Which of these do not form Grignard reagent(a.256) CH3F (b.256) CH3Cl(c.256) CH3Br (d.256) CH3I

Q.257 An organic compound A(C4H6Cl) on reaction with Na/diethyl ether gives a hydrocarbon, which on monochlorination gives only one chloro derivative. A is......

(a.257) t-butyl chloride (b.257) s-butyl chloride(c.257) Isobutyl chloride (d.257) n-butyl chloride

Q.258 Among the following the most reactive towards alcoholic KOH is......(a.258) CH2 = CHBr (b.258) CH3COCH2CH2Br(c.258) CH3CH2Br (d.258) CH3CH2CH2Br

Q.259 Which one of the following possess highest m.pt.(a.259) Chlorobenzene (b.259) o-dichlorobenzene(c.259) m-dichlorobenzene (d.259) p-dichlorobenzene

Q.260 Which chlorine atom is more electronegative in the following(a.260) CH3-Cl (b.260) CH3 – CH2 - Cl

(c.260) (d.260) Q.261 What would be the product formed when 1-Bromo-3-chloro cyclobutane reacts with two equivalents of metallic sodium in ether

(a.261) (b.261) (c.261) (d.261) Q.262 Preparation of alkyl halides in laboratory is least preferred by

(a.262) Halide exchange (b.262) Direct halogenation of alkanes (c.262) Treatment of alcohols (d.262) Addition of hydrogen halides to alkenes

Q.263 An alkyl halide may be converted into an alcohol by (a.263) Addition (b.263) Substitution (c.263) Dehydrohalogenation (d.263) Elimination

Q.264 The C-Cl bond in chlorobenzene as compared with C-Cl bond in methyl chloride is......

(a.264) Longer and weaker(b.264) Shorter and weaker(c.264) Shorter and stronger(d.264) Longer and stronger

Q.265 A salt solution is treated with chloroform drops. Then it is shaked with chlorine water. Chloroform layer becomes violet. Solution contains

(a.265) (b.265) (c.265) Br- ion (d.265) I- ion

Q.266 The following reaction belongs to (CH3)3C –Br (CH3)3-C-OH (a.266) Elimination reaction (b.266) Substitution reaction

(c.266) Free radical reaction (d.266) Displacement reactionQ.267 The order of reactivities of methyl halides in the formation of Grignard reagent is

(a.267) CH3I > CH3Br > CH3Cl (b.267) CH3Cl > CH3Br > CH3I (c.267) CH3Br > CH3Cl > CH3I (d.267) CH3Br > CH3I > CH3Cl

Q.268 Identify Z in the following series

(a.268) CH3CH2CN (b.268) (c.268) BrCH2 –CH2CN (d.268) BrCH = CHCN

Q.269 The total number of stereoisomeric forms of C6H6Cl6 known is...... (a.269) 6 (b.269) 7 (c.269) 8 (d.269) None of these

Q.270 The correct order of C – X bond polarity is...... (a.270) CH3Br >CH3Cl > CH3I (b.270) CH3I > CH3Br > CH3Cl (c.270) CH3Cl > CH3Br >CH3I (d.270) CH3Cl > CH3I > CH3Br

Q.271 The order of reactivities of the following alkyl halides for a SN2

reaction is...... (a.271) RF > RCl > RBr > RI

(b.271) RF > RBr > RCl > RI (c.271) RCl > RBr > RF > RI (d.271) RI > RBr > RCl > RF

Q.272 Which of the following reactions doesn’t give benzene

(a.272) C6H5N2Cl

(b.272) C6H5N2Cl

(c.272) C6H5N2Cl + H3PO2 + H2O (d.272) All of these

Q.273 Benzene hexachloride is prepared from benzene and chlorine in sunlight by

(a.273) Substitution reaction (b.273) Elimination reaction(c.273) Addition reaction (d.273) Rearrangement

Q.274 Carbon-halogen bond is strongest among the following(a.274) CH3Cl (b.274) CH3Br(c.274) CH3F (d.274) CH3I

Q.275 Which of these do not undergo Wurtz reaction(a.275) C2H5F (b.275) C2H5Br(c.275) C2H5Cl (d.275) C2H5I

Q.276 When ethyl bromide reacts with sodium acetylide the main product is......

(a.276) 1-butane (b.276) 1-butene (c.276) 1-butyne (d.276) 2-butene

Q.277 C2H5I and Ag2O reacts to produce (a.277) C2H6 (b.277) C2H5 - C2H5

(c.277) C2H5 – O- C2H5 (d.277) C2H5 – CH3

#Solution#Introduction of Halogen containing compounds

#2# % of Br

or approx. 75%#3# Gem-dihalides are those in which two halogen atoms are attached

on the same carbon atom.

#6# Isopropyl chloride chlorine atom is attached to 2º carbon atom.

#7# (X = Cl, Br, I) #11# Neohexyl chloride is a primary halide as in it Cl-atom is attached to

a primary carbon.

#12#

13. (b)

Preparation of Halogen containing compounds

#15#

#18# CH3COOAg + Br2 CH3Br + AgBr +CO2

#20# C2H5OH+SOCl2 C2H5Cl+SO2+HCl

#27#CH2=CH2+BR2

#28# C3H8 + Cl2 C3H7Cl + HClThis is an example of substitution reaction. Hydrogen atom of alkane is replaced by halogen atom.

#29# CH≡ CH + HCl →CH2=CHCl CH3CHCl2#30# R-OX+HX →R-X+H2O

Reactivity order of alcohols for this reaction 3º > 2º >1º Reactivity order of halogen acids R-I > R-Br > R-Cl

yellow ppt.

#31#

#32#

#34#

#35#

#36#

#37##38# CaOCl2 + H2O →Ca(OH)2 +Cl2

#39# CH3CH2OH+Cl2 →CH3CHO+2HCl

#40#

#42#

#43# #44# CH3COCH3 + 3I2 +4NaOH →

CHI3+3Na+CH3COONa+3H2O

#45#

#46#

#47#

#48#

#56##58# DDT is prepared by heating chlorobenzene and chloral with

concentrated sulphuric acid

#59# Acetone forms chloroform when heated with bleaching powder. CaOCl2+H2O →Ca(OH)2+Cl2 CH3COCH3+3Cl2 →CCl3COCH3+3HCl

#60# Cl2+H2O →2HCl+O

#61# CaOCl2+H2O →Ca(OH)2+Cl2CH3CH2OH+Cl2 →CH3CHO+HCl

#62# When ethylene reacts with bromine, it forms ethylene dibromide.

#63# The chlorination of alcohol by SOCl2 (thionyl chloride) is the best method for the preparation of alkyl halides as in this method all the other product are gaseous and thus halides are obtained on quite

pure state

#64##65# DDT is formed by reaction of chloral with chloro benzene.#67# NBS is a selective brominating reagent since it normally

brominates the ethylenic compounds in the allylic position.

Properties of Halogen containing compounds

#68# As –CCl3 is a m-directing group.

#69# Ag2O+H2O →2AgOH C2H5Br+AgOH →C2H5OH+AgBr

#70#

#71#

If NH3 is in excess, then 1º amine will be the main product, if C2H5Cl is in excess then mixture of 1º,2º,3º and quaternary amine is obtained.

#72# #73# COCl2 carbonyl chloride is commonly called as phosgene. #74# C2H5NH2 + CHCl3+3KOH →

#75#

#76#

#78#

#80# Chlorobenzene is less reactive than benzyl

chloride

In chlorobenzene the lone pairs present on Cl atom get involved in resonance with π electrons of benzene due to which C-Cl bond acquires double bond character Hence, reactivity decreases.

#81# CH3-Cl> CH3-CH2-Cl>

#82# CHI3 gives a yellow ppt. of AgI.

#84# + CCl4+4NaOH→4NaCl+2H2O

#85# (X=Cl,Br,I)

#86#

CH3ONa →CH3O-+Na+

methoxide ion (CH3O-) is a strong base, therefore it abstract proton from 3º alkyl halide and favours elimination reaction.

#87# #88# CCl4 +AgNO3 → No reaction CCl4 is a covalent compound. Therefore does not provide Cl- ions.

#89#

#90# C6H5 - CH2 – Cl + KCN(aq) → C6H5 - CH2 – C ≡ N + KCl

#91#

#92#

#94

#

#95#

#96#

#97##99# CCl4 is a covalent compound, Hence it does not give Cl- ion in

solution. CCl4 + AgNO3→No reaction

#100#

#101#

#102#

#103#

Ag-O-N=O is a covalent compound. Therefore, attack of

nucleophile occurs through Nitrogen atom. Hence, nitroethane is formed.

#107# C2H5Br C2H5CN C2H5CH2NH2(C3H7NH2)

X=KCN,Y=LiAlH4

#108# CH3CH2CH2CH2 – Cl + KOH(alc.)→

#109# CH2=C=C=CH2

#110# +3KCl + 3H2O

#111#

#113#

#114#The functional isomer of ethyl isocyanide is ethyl cyanide C2H5-C≡N.

#115# C2H5Br+alc.KOH→ C2H4+H2O+KBr

#116#

#117# White ppt of AgCl are obtained.

#118# It means –CHO group is present.

It means only one –CHO group is present.

C2H5OH+Cl2→CH3CHO+2HCl

#120# Ethanol cannot undergo dehydrohalogenation.

#121#

#122#

#123# C2H5Cl+KCN

#124#

#125#

#126#

#127# #128# Before using the sample of chloroform as an anaesthetic, it is

tested by treating with aq. solution of AgNO3. A pure sample does not give ppt with aq. AgNO3.

#129# Alkyl halide gives alkene on elimination, reaction takes place in presence of alc. KOH.

CH3CH2Br+Alc.KOH→CH2=CH2+KBr+H2OThere are two types of elimination reactions.(a) E1→ Unimolecular elimination(b) E2→ Bimolecular elimination

#130# (i) Ethyl alcohol (ii) Phenol

HBr

#131#

When alkyl halide reacts with alc. KOH then it favours elimination reaction (Dehydrohalogenation). Since, trans pentene-2 is more symmetrical than cis isomers. Hence, it is main product.

#133##137# Alkyl halide reacts with Mg in presence of dry ether to give alkyl

magnesium halide which is also called as Grignard reagent. This reaction is also called as Grignard’s reaction.

#138#

#143#

#146# If CHCl3 sample contains phosgene (COCl2) then it will give a

white ppt. When treated with cold AgNO3.

#147# Because has four methyl groups on the corner so it can produce for derivatives.

#151# CHCl3 + AgNO3 → No react CHCl3 is a covalent compound. It does not ionize in water.

+Cl2

CH3

Toluene

Sunlight

CH2Cl

+HCl

CCl3

+2HCl+ 2Cl2Sunlight

+ 3NaOH

CCl3

+ 3NaCl

C(OH)3

COOH

+ H2ONaOH

COONa

H2O +

#153# Vinyl chloride is less reactive than allyl chloride due to resonance effect.Order of nucleophilicity amongst the halide ion are as I->Br->Cl-.

#154#

#156#

#158#

#159#

#160#

#161##162# CHCl3 + 6Ag + Cl3CH → CH ≡ CH + 6AgCl#163# CO is poisonous gas.#165# C6H6Cl6 + 3KOH → C6H3Cl3 +3KCl +3H2O

Thus Benzene hexahalides decomposes when heated with alc. KOH and yield trichloro benzene.

#166# C2H5-I + AgNO3→C2H5ONO2+AgI #167# We know that CHCl3+HF → CHF3+3HCl. Thus in this reaction

the compound obtained in fluoroform (CHF3). As we know molecular weight of CHF3 =70.

#169# #170# Density of alkyl halide increases as the size of halogen atom

increases. RF< RCl< RBr < RI

#171# Due to resonance partial double bond character is created on vinyl chloride. So, chlorine atom is not replaced easily.

#172# #175#

#176# #177# It is Wurtz reaction in which hydrocarbon formed when alkyl halide

react with Na metal in dry ether.

#178# C3H7Br+KCN→C3H7CN+KBrIn IUPAC system the carbon of functional group also take in numbering. So C3H7CN is butane nitrile.

#179# It is Wurtz fittig reaction

#180# Because it float over chloroform and prevent its oxidation.#181# Due to the presence of electron rich methoxy group (+I) at p-

position the polarity increase on C-X bond by which it becomes more reactive towards nucleophillic attack of ethanol, p-nitro and chloro are electron deficient group decrease the polarity of C-X bond. Hence by them it become difficult to react with ethanol due to less polarity. Methyl group is less electron rich than methoxy group.

#182# When chloroform is treated with concentrated nitric acid, its hydrogen is replaced by nitro group.

#183# Alkyl halides give alkane when react with sodium in ether. This is called Wurtz reaction.

#184# Chloroform is oxidised to a poisonous gas, phosgene (COCl2) by atmospheric gas.CHCl3 + O → COCl2 + HCl

#185# When chloroform reacts with HNO3 product formed are chloropicrin or tear gas and water.

#186# We know that CH3CH2Cl+KOH→CH2=CH2+KCl+H2O Thus in this reaction ethene (C2H 4 ) is produced.

#187# We know that

Thus in this reaction acetylene (HC≡CH) is produced.#188# Alkyl halide on reaction with dry silver oxide furnish ether.

Benzene

+ 3Cl2h

ClClCl

ClClCl

BHC

CH2Br

Ionization– Br

CH2 CH2 CH2 CH2

#189# Acylation or alkylation of aromatic compound in presence of AlCl3 is known as Friedal-craft reaction.

#190# Any substance which when added to a chemical reaction inhibit or decrease the rate of reaction is called negative catalyst. In CHCl3 when two percent ethanol is added, it stops the formation of carbonyl chloride. So ethanol acts as negative catalyst.

#191# When benzene is heated with chlorine in the presence of sunlight, it form benzene hexachloride.

#192# #193# It is a common method to prepare alkanes. Methane cannot

be prepared by Wurtz reaction.

#194# At room temperature iodoform is the yellow solid.#195# Benzyl chloride are far more reactive than alkyl halide towards

nucleophilic substitution reaction due to the reason that the carbocation formed after the removal of halide ion is stabilized by resonance.

#196# On hydrolysis, ethylene dichloride gives ethylene glycol. While ethylidine chloride give acetaldehyde.

#198#

#199#

#200# #205# Alkyl halide is best converted to alkene by mean of

elimination reaction in form of dehydrohalogenation.

#206# ?Alkyl halide is 1°.Keep in mind 1° halide give product by SN 2 / E – 2 mechanism and 1° halide always gives substitution reaction except when strongly hindered base is used.

ex.: With it gives mainly elimination.The reaction involves carbocation intermediate.

i.e. but as it is a primary carbocation it will rearrange to give a tertiary carbocation, which completes the reaction

Stability of carbocation : 3° > 2° > 1° > It is because the stability of a charged system is increased by dispersal of the charge. The more stable the carbocation, the faster it is formed.N.B. – Rearrangement can be done in two ways.

Therefore,

#207# According to Saytzeff's rule, the major product will be that one which contains more number of substituents around the double bond.

#208# (CH3)3COH + PhMgBr ⃗ PhH + (CH3)3COMgBr#209# R2CuLi + R’X→R-R’+R-Cu+LiX#210# CH3F, CH3Cl, CH3Br and C2H5Cl are gases at room temperature.

CH3I is a liquid at room temperature and solidifies at –66.5°C.#211# The alkyl halides are highly reactive, the order of reactivity is

Iodide > bromide > chloride > (nature of the halogen atom).Tertiary > secondary > primary.Thus 2-bromopropane is the given option.

#212# Grignard reagent gives addition reactions with compounds containing C=O,-C≡N and C=S groups.

#213# Formation of A is a electrophilic addition reaction (i) HBr→H+ + Br-

CH=CH 2

(ii) +H+→C6H5CHCH 3

+

Formation of B is a free radical addition reaction

(i)

(ii)

(iii)

Uses of Halogen Containing Compounds

#215#

#216# #221# DDT

#224# #225# Freon (CCl2F2) is an odourless, non-corrosive, non toxic gas

which is stable even at high temperatures and pressures. It has low b.Pt, low specific heat and can be easily liquified by applying pressure at room temperature. It is therefore, widely used in refrigerant (cooling agent) in refrigerators and air conditioners.

Benzene

+ 3Cl2 sunlight

ClClCl

ClClCl

BHC

#228##231# Its vapours are non inflammable (i.e. do not catch fire). Hence

used as fire extinguishers under the name pyren.#232# Iodoform is used as an antiseptic for dressing wounds. When it

comes in contact with skin (organic matter), Iodine is set free which responsible for antiseptic action.

#233# Inhalation of CHCl3 vapours produces loss of consciousness and is therefore, used as a general anaesthetic agent in surgery.

#235# CCl4 is stable to red heat. Its vapours are highly non-inflammable i.e. do not catch fire. It is because of this property CCl4 is used as a fire extinguisher. But now a days its use as a fire extinguisher is restricted because with water vaporous. It forms highly poisonous phosgene gas

#236# Benzene hexachloride is an insecticide generally known as gammexane. It is obtained by the following reaction

#238# Chlorofluorocarbon is used in air-conditioning and in domestic refrigerators for cooling purposes. Its main drawback is this, it is responsible for ozone depletion.

Critical Thinking Questions#239# CH3Cl have one Cl atom which is more electronegative so it

will have highest dipole moment.

#240#

#241##242# As a result of resonance, the carbon-chloride bond acquires

some double bond character. Hence, vinyl chloride does not undergo nucleophillic substitution reactions.

#243#

+

H R

R

+

H R

+ AlCl4–

R

+ AlCl3 + HCl

OH+ CHCl3 + 3NaOH

OH

CHO+ 3NaCl + 2H2O

Salicylaldehyde

#244# % of chlorine

Chloral (CCl3CHO)

Pyrene (CCl4) Highest

Gammexene (C6H6Cl6) #245# SN2 Substitution nucleophilic bimolecular order of different alkyl

halides. 1º > 2º > 3º SN1 Substitution nucleophilic unimolecular order of different alkyl

halides, 3º >2º > 1º. #246# aaaeee form is the most powerful insecticide form of C6H6Cl6.

#247#Cl is more electronegative than C by which it form anion and hydrocarbon form cation.

#248# New carbon-carbon bond formation take place in Friedel Craft’s alkylation and Reimer-Tiemann reaction. In Friedel Craft’s alkylation following mechanism involve

⇌

Here new C–C bond formed between carbon of benzene ring and alkyl group.Similarly in Reimer-Tiemann reaction.

Here new C–C bond formed between carbon of benzene ring and –CHO

group.

#249##250# Only 1° alkyl halides, i.e. CH3Br undergoes SN2 reaction.#251# Wurtz reaction gives ethane

Similarly C2H5Cl reduced by LiAlH4 to give ethane

Br

Br1, 2 dibromo cyclohexane Cyclohex-diene

2HBr-

ogenationDehydrohal

+ Cl2 + Cl2

all –CH3 gives same monochloro –CH2Cl derivative, so it is tertiary butyl alcohol

Br

Cl

2Na 2Na + 2e–

Cl

⊖..

#252#

#253##254# CH3-O-CH3+PCl5→2CH3Cl+POCl3

CH3CH2OH+PCl5→CH3CH2Cl+HCl+POCl3So, both reaction carried out by PCl5

#255#

#256# The C–F bond energy is maximum in CH3F. Thus fluoride is the

less reactive to form the grignard reagent with Mg.

#257#)

#258# The polarity between C-X bond increase by increasing the +I effect which increase by increasing the alkyl group by which X of C-X easily eliminate. In CH3CH2CH2Br the polarity is maximum due to 3 alkyl group while in rest polarity decrease due to the presence of double bond, presence of –CO group (–I) and less no. of alkyl group.

#259# p-dichlorobenzene molecule has symmetrical structure. It can fit well in its crystal lattice. The intermolecular forces of attraction are strong. Hence, it possesses highest melting point.

#260# Due to +I effect of 3 alkyl group in option (d), the chlorine atom occupy the maximum charge in it so it is more electronegative.

#261# It is the example of Wurtz reaction.

Not shown by alkyl halide(saturated compound)

HXCHCHR Alkene

2

HXCHCHR Alkene

2

Additionreaction

Dehydrohalogenation

Alc.KOH

EliminationAlc.KOH

aq.KOH

Substitution HXOHCHCHR

Alcohol22

2 2Alkyhalide

R CH CH X

self evaluation test#262# Direct halogenation of alkenes is not preferred because in it a

mixture of monohalogen, dihalogen, trihalogen and tetrahalogen substituted product is obtained which is difficult to separate.

eg.

#263#

#264# In chlorobenzene C – Cl bond acquires partial double bond character because of resonance.

#265# 2NaI +Cl2→2NaCl+I2 (Dissolves in CHCl3 to give violet colour)Chlorine displaces iodine from salt. The iodine get dissolve in CHCl3

or CCl4 to produce violet colour.

#266#Here Br substitute by -OH group.

#267# Reactivity towards grignard reagent are as under CH3I> CH3Br>CH3Cl

#268#

#269# C6H6Cl6 has 8 stereoisomer.#270# The C-X bond polarity order are as under CH3Cl>CH3Br>CH3I#271# The order of reactivity of alkyl holides for SN2 reaction is

R-I>R-Br>R-Cl>R-F

#272#

#273# #274# CH3F>CH3Cl>CH3Br>CH3I

#275#

#276# Thus in this reaction 1-butyne is main product.

#277# C2H5I and Ag2O reacts as below

Thus, C2H5-O-C2H5 is produced.