CHEMISTRY

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CONTENTSTitle1. ROUTES FOR SYNTHESIS OF ORGANIC COMPOUNDS 2. ASSESSMENT EXERCISE A 3. ANSWERS FOR ASSESSMENT EXERCISE A 4. DIAGNOSTIC EXERCISE A 5. ANSWERS FOR DIAGNOSTIC EXERCISE A 6. ASSESSMENT EXERCISE B 7. ANSWERS FOR ASSESSMENT EXERCISE B 8. DIAGNOSTIC EXERCISE B 9. ANSWERS FOR DIAGNOSTIC EXERCISE B 10. ASSESSMENT EXERCISE C 11. ANSWERS FOR ASSESSMENT EXERCISE C

Page3 - 11 12 - 13 14 - 15 16 17 18 - 20 21 22 - 23 24 25 - 26 27 - 29 30 - 34

ALKENES

2

BENZENES

METHYLBENZENES

3

ALCOHOLS

HALOALKANES

4

PHENOLS

ALDEHYDES5

KETONES

BENZALDEHYDES

6

CARBOXYLIC ACIDS

BENZOIC ACIDS

ESTERS7

AMINES

PHENYLAMINE

AMINO ACIDS8

GRIDNARD REAGENTS

ACYL CHLORIDES

NOTE 2

9

SAYTZEFFS RULEWhen the dehydration of an alcohol produces a mixture of alkenes, the identity of the major product obtained may be predicted by Saytzeffs rule. This states that the alkene containing the greater number of alkyl substituents is the predominant product.

MARKOVNIKOFFS RULEStates that the more electronegative atom (the chlorine atom of HCl) becomes more attached to the carbon atom (of the unsymmetrical alkene) containing fewer hydrogen atoms. The rule applies to the addition of water, sulphuric acid, chloric (I) acid (HOCl) and bromic (I) acid (HOBr) as well as to the addition of hydrogen halides to unsymmetrical alkenes.

The test for the functional groupFunctional group 1 C=C Chemical test / observations Reagent: Bromine in CCl4 Condition : Room temperature Decolourisation of bromine occurs immediately 2 ROH CH2=CH2 + Br2 CH2BrCH2Br (i)Reagent : PCl5 Condition : Room temperature White fumes of HCl liberated ROH + PCl5 RCl + POCl3 + HCl (g) (i) Reagent : Na Condition : Room temperature Hydrogen gas liberated 2ROH + 2Na 2RONa + H2 (g) or 2RCOOH + 2Na 2RCOONa + H2 (g) 3 O C Reagent : 2,4-dinitrophenylhydrazine Condition : Room temperature Yellow / orange precipitate formed 10 or RCOOH + PCl5 RCOCl + POCl3 + HCl (g)

O2N C=O + H2NNH O2N C= NNH NO2 + H2O(l) NO2

4

O COH

Reagent :Na2CO3(aq) Condition : room temperature Carbon dioxidegas liberated 2RCOOH+Na2CO3(aq)2RCOONa+ CO2(g) H2O(l) Reagent : Bromine water Condition : room temperature OH White precipitated of 2,4,6-tribromophenol or (2,4,6-tribromophenylamine ) formed. Decolourisation of bromine water NH2 OH + 3Br2 (aq) Br Br OH Br + 3HBr

5

Phenol or phenylamine

Assessment Exercise A 1. Give the equation, the conditions needed and the names of the products when (a) but-2-ene reacts with hydrogen bromide (b) propene reacts with bromine in tetrachloromethane 11

(c) cyclohexene reacts with hydrogen (d) propene reacts with concentrated sulphuric (VI) acid 2. Write the structural formula formed in the following reactions. (a) (b) (c) (d) + CH3CH2Br in the presence of FeBr3 + COCl in the presence of AlCl3

+ HNO3/H2SO4 at 50oC + Cl2 in the presence of iron catalyst

3. Suggest the reagents and conditions necessary to convert CH3CH2Br into (a) CH3CH2NH2 (b) CH3CH2OH (c) CH2 = CH2 (d) CH3CH2MgBr 4. Draw the structures of the product when methylmagnesium bromide, CH3MgBr in dry ether reacts with the following compounds followed by hydrolysis with dilute acid. (a) methanal, HCHO (b) CH3CHO (c) CH3COCH3 (d) CO2 5. Draw the structures of the products of the following reactions. (a) oxidation of 2-methylpropan-1-ol (b) butan-2-ol with PCl5 (c) propan-1-ol reflux with ethanoic acid in the presence of concentrated sulphuric (VI) acid (d) heating cyclohexanol with concentrated phosphorus (V) acid 6. Give the equation for the reaction between phenol, (a) sodium metal (b) sodium hydroxide (c) ethanoyl chloride, CH3COCl (d) bromine water 12 OH with

7. Give the reagents, conditions and the equations for the following conversions. (a) Ethanal, CH3CHO ethanal cyanohydrin, CH3CH(OH)CN (b) Propanal, CH3CH2CHO propanal oxime, CH3CH2CH=NOH (c) Propanone, CH3COCH3 propanone phenylhydrazone (d) Ethanal, CH3CHO ethanal 2,4-dinitropheylhydrazone 8. Write equations to show the reactions occurring between (a) ethanoic acid, CH3COOH and phosphorus (III) chloride, PCl3 (b) propanoic acid, CH3CH2COOH and lithium tetrahydridoaliminate (III) (c) methanoic acid and hydrogen gas over heated nickel (d) heating sodium ethanoate and soda lime 9. Suggest the reagents and conditions for the following conversions. (a) Methylamine, CH3NH2 methanol, CH3OH (b) Ethylamine, CH3CH2NH2 N-ethylethanamide, CH3CONHCH2CH3 (c) Ethylamine, CH3CH2NH2 diethylamine, (CH3CH2)2NH (d) Phenylamine, NH2 2,4,6-tribromophenylamine

10. State the observations for the following reactions. (a) Ethanol reacts with phosphorus (V) chloride (b) Propene reacts with bromine in tetrachloromethane (c) Butan-2-ol reacts with alkaline iodine (d) propanal reacts with ammoniacal silver nitrate solution (e) propanone with 2,4-dinitrophenylhydrazine

Answers (Assessment Exercise A)1(a) (b) (c) Equation CH3CH=CHCH3 + HBr CH3CH2CHBrCH3 CH3CH=CH2 + Br2 CH3CHBrCH2Br + H2 Conditions Room temperature Room temperature Ni catalyst, 150oC Name of product 2-bromobutane 1,2-dibromopropane cyclohexane

13

(d)

CH3CH=CH2 + H2SO4 CH3CH(OSO3H)CH3

cold

2-propylhydrogensulphate

2(a)CH2CH3

(b) C O

(c)

NO2

(d)

Cl

3(a) (b) (c) (d) 4(a) (b) (c) (d)

Reagents Concentrated ammonia in ethanol in a sealed tube Dilute NaOH(KOH) in ethanol KOH dissolved in ethanol Magnesium turning CH3CH2OH CH3CH(OH)CH3 (CH3)2C(OH)CH3 CH3COOH

Conditions Room temperature Reflux Reflux Dry ethoxyethane (ether)

5(a) (b) (c) (d)

(CH3)2CHCOOH CH3CH2CH(Cl)CH3 CH3COOCH2CH2CH3

Equation 6(a) (b) (c) 2 OH + 2Na 2 OH + NaOH ONa + H2 ONa + H2O + HCl

OH + CH3COCl CH3COO

14

(d) OH + 3Br2 Br

OH Br + 3HBr Br

7(a) (b) (c) (d)

Reagents KCN , dilute H2SO4 Hydroxylamine Phenylhydrazine 2,4-dinitrophenylhydrazine

Conditions 10 20oC Warm Room temperature Room temperature

Equation CH3CHO + HCN CH3CH(OH)CN CH3CH2CHO + H2NOH CH3CH2CHNOH + H2O CH3COCH3 + C6H5NHNH2 (CH3)2C=N-NHC6H5 + H2O CH3CHO + 2,4-DNPH CH3CH-(2,4-DNPH) + H2O

8(a) (b) (c) (d)

Equation 3CH3COOH + PCl3 3CH3COCl + H3PO3 CH3CH2COOH + 4[H] CH3CH2CH2OH + H2O HCOOH + 3H2 CH4 + 2H2O CH3COONa + NaOH CH4 + Na2CO3

9(a) (b) (c) (d)

Reagents NaNO2 , dilute HCl CH3COCl CH3CH2I in ethanol Bromine water

Conditions Room temperature Room temperature Heat in a sealed tube Room temperature

10(a) (b) (c) (d) (e)

Observations White fume of hydrogen chloride formed. Brown colour of bromine decolourised. Yellow solid (triiodomethane) formed. Silver mirror formed on the wall of the test tube. Yellow crystalline solid formed.

Diagnostic Exercise A 1. Give the equation, the conditions needed and the names of the products when (a) pent -2-ene reacts with hydrogen bromide (b) ethene reacts with bromine in tetrachloromethane (c) 4-methyl-cyclohexene reacts with hydrogen (d) but-1-ene reacts with concentrated sulphuric (VI) acid 15

2. Write the structural formula formed in the following reactions. (a) (b) (c) (d) + CH3Br in the presence of FeBr3 + CH3COCl in the presence of AlCl3 + concentrated HNO3 with concentrated H2SO4 catalyst at 50oC + Br2 in the presence of iron catalyst

3. Suggest the reagents and conditions necessary to convert CH3CH2CH2Br into (a) CH3CH2 CH2NH2 (b) CH3 CH2CH2OH (c) CH3CHCH2 (d) CH3CH2CH2MgBr 4. Draw the structures of the product when methylmagnesium bromide, C2H5MgBr in dry ether reacts with the following compounds followed by hydrolysis with dilute acid. (a) methanal, HCHO (b) CH3CHO (c) CH3COCH3 (d) CO2 5. Draw the structures of the products of the following reactions. (a) oxidation of 2-methylbutan-1-ol (b) pentan-2-ol with PCl5 (c) butan-1-ol reflux with ethanoic acid in the presence of concentrated sulphuric (VI) acid (d) heating 2-methylcyclohexanol with concentrated phosphorus (V) acid 6. Give the equation for the reaction between 4-methylphenol with (a) sodium metal (b) sodium hydroxide (c) ethanoyl chloride, CH3COCl (d) bromine water 7. Give the reagents, conditions and the equations for the following conversions. 16

(a) Propanal, C2H5CHO propanal cyanohydrin, C2H5CH(OH)CN (b) Ethanal, CH3CHO ethanal oxime, CH3CH=NOH (c) Butanone, C2H5COCH3 butanone phenylhydrazone (d) Butanal, C3H7CHO butanal 2,4-dinitropheylhydrazone 8. Write equations to show the reactions occurring between (a) propanoic acid, C2H5COOH and phosphorus (III) chloride, PCl3 (b) ethanoic acid, CH3COOH and lithium tetrahydridoaliminate (III) (c) butanoic acid, C3H7COOH and hydrogen gas over heated nickel (d) heating sodium propanoate, C2H5COONa and soda lime 9. Suggest the reagents and conditions for the following conversions. (a) Ethylamine, C2H5NH2 ethanol, C2H5OH (b) Methylamine, CH3NH2 N-methylethanamide, CH3CONHCH3 (c) Methylamine, CH3NH2 dimethylamine, (CH3)2NH 10. State the observations for the following reactions. (a) Propanol reacts with phosphorus (V) chloride (b) Ethene reacts with bromine in tetrachloromethane (c) Pentan-2-ol reacts with alkaline iodine (d) Ethanal reacts with ammoniacal silver nitrate solution (e) Butanone with 2,4-dinitrophenylhydrazine

Answers (Diagnostic Exercise A)

1(a) (b)

Equation C2H5CH=CHCH3 + HBr C2H5CH2CHBrCH3 CH2=CH2 + Br2 CH3CHBrCH2Br+ H2 CH3

Conditions Room temperature Room temperature Ni catalyst, 150 C coldo

Name of product 2-bromopentane 1,2-dibromoethane methylcyclohexane 2-butyl hydrogensulphate

(c) CH3 (d)

C2H5CH=CH2 + H2SO4 C2H5CH(OSO3H)CH3

17

2(a)CH3

(b) C-CH3 O

(c)

NO2

(d)

Br

3(a) (b) (c) (d)

Reagents Concentrated ammonia in ethanol in a sealed tube Dilute NaOH(KOH) in ethanol KOH dissolved in ethanol Magnesium turning

Conditions Room temperature Reflux Reflux Dry ethoxyethane (ether)

4(a) (b) (c) (d)

C2H5CH2OH CH3CH(OH)C2H5 (CH3)2C(OH)C2H5 C2H5COOH

5(a) (b) (c) (d)

CH3CH2CH(CH3)COOH CH3CH2CH2CH(Cl)CH3 CH3COOCH2CH2CH2CH3

CH3

Equation 6(a) 2 OH + 2Na 2 CH3 CH3 ONa + H2

18

(b)

OH + NaOH CH3

ONa + H2O CH3 OOCCH3 + CH3COCl + HCl CH3

(c)

OH

CH3 (d) OH + Br2 CH3 Br

OH Br CH3 + 2HBr

7(a) (b) (c) (d)

Reagents KCN , dilute H2SO4 Hydroxylamine Phenylhydrazine 2,4-dinitrophenylhydrazine

Conditions 10 20oC Warm Room temperature Room temperature

Equation C2H5CHO + HCN C2H5CH(OH)CN CH3CHO + H2NOH CH3CHNOH C2H5COCH3 + C6H5NHNH2 C2H5(CH3)C=N-NHC6H5 C3H7CHO + 2,4-DNPH C3H7CH-(2,4-DNPH)

8(a) (b) (c) (d)

Equation 3C2H5COOH + PCl3 3C2H5COCl + H3PO3 CH3COOH + 4[H] CH3CH2OH + H2O C3H7COOH + 3H2 C4H10 + 2H2O C2H5COONa + NaOH C2H6 + Na2CO3

9(a) (b) (c)

Reagents NaNO2 , dilute HCl CH3COCl CH3CH2I in ethanol

Conditions Room temperature Room temperature Heat in a sealed tube

10(a)

Observations White fume of hydrogen chloride formed.

19

(b) (c) (d) (e)

Brown colour of bromine decolourised. Yellow solid (triiodomethane) formed. Silver mirror formed on the wall of the test tube. Yellow crystalline solid formed.

ASSESSMENT EXERCISE B

1.

Give the reagents and conditions for the following sequence of reactions. (a) CH3 COOH COCl

(b) CH2 = CHCH3 CH3CHBrCH3 CH3CHOHCH3 20

(c)

CH3

COOH

(d) CH3Br CH3CN CH3COOH (e) CH3CH2Br CH3CH2CN CH3CH2CH2NH2 (f) BrCH2CH2Br NCCH2CH2CN HOOCCH2CH2COOH (g) (h) CH2I NO2 CH2OH NH2 CH2OOCCH3 NHCOCH3

(i) C2H5Br C2H5 MgBr C2H5C(OH)(CH3)2

2.

Write the reaction scheme to show how you would carry out the following conversions, by stating the reagents and conditions. (a) CH2 = CH2 CH2 CH2NH2

(b) CH3CH2Br CH3CHO (c) CH3CH2Cl CH3CH2COOH (d) CH3CH2OH HOCH2CH2OH (e) CH3CHOH BrCH2CH2Br (f) (g) Br CH2OH NHCO

NO2

(h) CH3I (CH3)2CHOH (i) BrCH2CH2Br H2NCH2CH2CH2CH2NH2

ANSWERS FOR ASSESSMENT EXERCISE B No. 1 (a) KMnO4/ H+, reflux ; PCl5, room temperature, (b) HBr gas, room temperature ; aqueous NaOH, reflux 21

(c) CH3I / AlCl3 , room temp. ; KMnO4/ H+, reflux (d) KCN / ethanol, reflux ; dil. H2SO4, reflux (e) KCN / ethanol, reflux ; H2 / nickel , 1800C (f) KCN / ethanol, reflux ; dil. H2SO4, reflux (g) aqueous NaOH, reflux ; CH3COOH, conc H2SO4, reflux (h) Sn / conc HCl, room temp. ; CH3COCl, room temp. (i) No. 2 Mg / ether, room temp. ; propanone / H3O+

I (a) CH2 = CH2

II CH3CH2Br

CH3CH2NH2

Step I : HBr gas , room temp Step II : conc NH3 / ethanol , heat (b) CH3CH2Br I CH3CH2OH II Step I : aq NaOH, reflux Step II : KMnO4 / H+ , heat I (c) CH3CH2Cl II CH3CH2CN CH3CH2COOH CH3CHO

Step I : aq KCN / ethanol, reflux Step II : dil H2SO4 , reflux I (d) CH3CH2OH II CH2=CH2 HOCH2CH2OH

Step I : conc H2SO4, 180oC Step II : KMnO4, room temp. I (e) CH3CH2OH II CH2=CH2 BrCH3CH2Br

Step I : conc H2SO4 , 180 oC Step II : Br2 /CCl4 , room temp.

(f)

I Br Step I : Mg / ether

II MgBr

CH2OH

Step II : methanal / H3O+ (g) I NO2 I II NH 2 NHCO II I I 22

Step I : Sn / conc HCl , room temp. I

Step II : I (h) CH3I

COCl, room temp. II CH3MgBr (CH3)2CHOH

Step I : Mg / ether Step II : CH3CHO / H3O+ I II (i) BrCH2CH2 Br NCCH2CH2CN Step I : aq KCN / ethanol, reflux Step II : H2 / nickel, 180 oC H2NCH2CH2CH2CH2NH2

DIAGNOSTIC EXERCISE B 1. Give the reagents and conditions for the following sequence of reactions. (a) CH2CH3 COOH COCl

(b) CH3CH = CHCH3 CH3CH2CHBrCH3 CH3CH2CHOHCH3

23

(c)

CH3 CH3

CH3 HOOC

COOH

(d) CH3CH2Br CH3CH2CN CH3 CH2COOH (e) CH3Br CH3CN CH3CH2NH2 (f) BrCH2CH2CH2Br NCCH2CH2CH2CN HOOCCH2CH2CH2COOH (g) (h) CH2Br NO2 CH2OH NH2 CH2OOCCH3 NHCOCH2CH3

(i) C2H5Br C2H5 MgBr C2H5CH(OH)(CH3)

2.

Write the reaction scheme to show how you would carry out the following conversions, by stating the reagents and conditions. The conversion may involve more than one step. (a) CH2 = CH2 CH3CH2CH2NH2

(b) CH3CH2Br CH3COOH (c) CH3CH2Br CH3CH2COOH

(d) CH3CH2CH2OH CH3CHBrCH3 (e) CH3CH2Br CH3CH2OOCCH3 (f) (g) O2N HOOC COOH NHCOCH3

NO2 H3CCOHN

(h) CH3Br (CH3)2CHOH (i) CH2CH2 I H2NCH2CH2CH2CH2NH2

ANSWERS FOR DIAGNOSTIC EXERCISE B 1 (a) KMnO4/ H+, reflux ; PCl5, room temperature, (b) HBr, room temperature ; aqueous NaOH, reflux 24

(c) CH3I / AlCl3 , room temp. ; KMnO4/ H+, reflux (d) KCN / ethanol, reflux ; dil. H2SO4, reflux (e) KCN / ethanol, reflux ; H2 / nickel , 1800C (f) KCN / ethanol, reflux ; dil. H2SO4, reflux (g) aqueous NaOH, reflux ; CH3COOH, conc H2SO4, reflux (h) Sn / conc HCl, room temp. ; CH3CH2COCl, room temp. (i) Mg / ether, room temp. ; CH3CHO / H3O+

2

I (a) CH2 = CH2

II III CN CH3CH2Br CH3CH2CN / Step I : HBr, room temp Step II : KCN / ethanol, reflux Step III : H2 / nickel , 1800C

CH3CH2CH2NH2

(b) CH3CH2Br I CH3CH2OH II Step I : aq NaOH, reflux Step II : KMnO4 / H+ , reflux I (c) CH3CH2Br II CH3CH2CN

CH3COOH

CH3CH2COOH

Step I : aq KCN / ethanol, reflux Step II : dil H2SO4 , reflux I (d) CH3CH2CH2OH II CH3CH=CH 2 CH3CHBrCH3

Step I : conc H2SO4, 180oC Step II : HBr, room temp. I (e) CH3CH2Br II CH3CH2OH CH3CH2OOCCH3

Step I : aq NaOH, reflux Step II : CH3COOH, conc H2SO4 , reflux

(f)

I

CH3

II H3C

III CH3 HOOC

COOH

Step I : CH3Br / AlCl3 , room temp. Step II : CH3Br / AlCl3 , room temp. I Step III : KMnO4 / H+ , reflux I II I 25 I

(g) O2N

I NO2

H2N

II NH2 H3CCOHN

NHCOCH3

Step I : Sn / conc HCl , room temp. Step II : CH3COCl, room temp. I (h) CH3Br II CH3MgBr (CH3)2CHOH

Step I : Mg / ether Step II : CH3CHO / H3O+ I (i) CH3CH2 I III IV II CH2CNCH2CN CH2 = CH2 CH2BrCH2Br

H2NCH2CH2CH2CH2NH2 Step I : NaOH / ethanol, reflux Step II : Br2 / room temp Step III : aq KCN / ethanol, reflux Step IV : H2 / nickel, 180 oC

Assessment Exercise C 1. State the reagents and conditions (including the catalyst, if any) for the reactions I to V in the scheme below. I CH3 CH CH2 CH2OH CH3 CH CH2 COOH 26

CH3 III

CH3 II

CH3 CH CH2 = CH2 CH3 IV CH3 CH CH2 CH3 CH3 OH Answers: Reactions I II III IV V Reagents V

CH3 CH CH2 COOC2H5 CH3

CH3 CH C CH3 CH3 O

Conditions

2. State the reagents, conditions and chemical equations for the conversions as shown in the following scheme. ACH3

B

CH2Cl

C

CH2OH

DCONH2 COO-NH4+ COOH

F

E

A

Answers: Reactions A B 27 Reagents Conditions Equations

C D E F 3. Draw the structures of the products for the reactions as shown in the following scheme.NaNO2, dilute HCl Room temperature MnO4-/H+, Reflux

Ethanolic NH3 Heat in sealed tube

Dilute KOH, Reflux CH3COOAg Warm

C2H5OH, Conc. H2SO4 Reflux

C2H5BrEthanolic KCN Reflux Mg in ether

Ethanolic NaOCH3 Heat

H H I I CH=CH CH2 C = C CH2OH CH3 Compound A 4. (a) A compound A has the structure shown above. Write the formula of the products formed when A is (i) shaken with aqueous bromine (ii) treated with phosporus (V) chloride at room temperature. (iii) boiled under reflux with excess acidified aqueous potassium dichromate (VI) 28

CH3 I

H3C

CH2

Compound B

(b) Describe what might be observed and give the structural formulae of the products when compound B reacts with (i) bromine in inert solvent (ii) cold, acidified dilute potassium manganate (VII) 5. Describe a simple chemical test to distinguish between the following pairs of compounds. State the reagents used, conditions of reactions, and observations. Write equations for the reactions involved. (a) (b) (c) (d) . (e) (f) (g) (h) CH3CHOHCH3 and CH3OH CH3COCH2CH3 and CH3CH2COCH2CH3 CH2CH3 and CH2OH and CH2Cl and OH Cl

CH3CH2CHO and CH3COCH3 CH3CH2NH2 and CH3CH2CONH2 CH3CH2COOH and CH3COOCH3

Answers: (Assessment Exercise C)

1.

Reactions I II III IV V

Reagents Acidified KMnO4 Ethanol KOH in ethanol Steam Acidified KMnO4 Reflux

Conditions

Reflux with concentrated H2SO4 Reflux Concentrated H3PO4, 330oC, 60 atm Reflux

29

2

Reactions

Reagents CH3Cl

Conditions AlCl3 Warm

Equations CH3

A

+ CH3Cl

+

HCl

B

Cl2

Ultraviolet light

CH3

+ Cl2

CH2Cl

+

HCl

C

Dilute KOH in ethanol

Reflux

CH2Cl + KOH

CH2OH + KCl

D

CH2OH Acidified KMnO4 Reflux + [O]

COOH +

H2O

E

(NH4)2CO3

Room temperature 2

COOH + (NH4)2CO3 2

COO-NH4+ + CO2 + H2O

F

_

Heating

COO-NH4+

CONH2 + H2O

3.C2H5NH2

NaNO2, dilute HCl Room temperature

C2H5OH

MnO4-/H+, Reflux

CH3COOH

Ethanolic NH3 Heat in sealed tube

Dilute KOH, Reflux CH3COOAg Warm

C2H5OH, Conc. H2SO4 Reflux

C2H5Br Ethanolic KCN Reflux

CH3COOC2H5

Mg in ether

Ethanolic NaOCH3 Heat

30

C2H5CN

C2H5MgBr

C2H5OCH3

4. (a)(i)

I Br

H H I I CH -I CH CH2 C - C CH2OH BrI Br I Br

CH3

H H I I CH=CH CH2 C = C CH2Cl (ii) CH3

(iii)

H H I I CH=CH CH2 C = C COOH CH3

(b) (i) CH3 BrBr Br

H3C (ii)

CH2Br

CHOH 3OH OH

31

H3C 5. (a) Reagent : I2/ NaOH(aq) Condition : Heat / Warm

CH2OH

For CH3CH(OH)CH3,pale yellow precipitate of triiodomethane, CHI3, is formed. For CH3OH, no visible reaction. I2/ NaOH(aq) CH3CH(OH)CH3 (b) Reagent : I2/ NaOH(aq) Condition : Heat / Warm For CH3COCH2CH3 ,pale yellow precipitate of triiodomethane, CHI3, is formed. For CH3CH2COCH2CH3, no visible reaction. I2/ NaOH(aq) CH3COCH2CH3 (c) Reagent : KMnO4 /H+ Condition : Heat For C6H5CH2CH3 , (i) decolourisation of KMnO4 solution occurs. (ii) white precipitate of benzoic acid , C6H5COOH, is formed. For C6H6 no visible reaction. KMnO4 /H+ C6H5CH2CH3 + 6[O] C6C5COOH + CO2(g) + 2H2O(g) CHI3(s) + CH3CH2COOCHI3(s) + CH3COO-

(d) Reagent : Bromine water, Br2(aq) Condition : Room Temperature For C6H5OH , (i) decolourisation of bromine water occurs. (ii) white precipitate of 2,4,6-tribromophenol is formed. For C6H5CH2OH, no visible reaction. Br OH + 3Br2(aq) Brv OH Br (e) Reagent : AgNO3(aq) / ethanol 32 + 3HBr(g)

Condition : Warm For C6H5CH2Cl, white precipitate of AgCl is formed. For C6H5Cl, no visible reaction. Ag+(aq) + Cl-(aq) AgCl(s) (f) (i) Reagent : I2/ NaOH(aq) Condition : Heat / Warm For CH3COCH3 ,pale yellow precipitate of triiodomethane, CHI3, is formed. For CH3CH2CHO, no visible reaction. I2/ NaOH(aq) CH3COCH3 warm (ii) Reagent : Fehlings solution / Cu2+(aq) Condition : Heat For CH3CH2CHO, brick red precipitate of Cu2O is formed. For CH3CH2CHO, no visible reaction. Fehlings solution CH3CH2CHO + Cu (aq) Heat (g) Reagent : NaOH(aq) Condition : Heat For CH3CH2CONH2 , ammonia gas is liberated. For CH3CH2NH2, no visible reaction. CH3CH2CONH2 + NaOH(aq) Heat CH3CH2COO-Na+ + NH3(g)2+

CHI3(s) + CH3COO-

CH3CH2COO- + Cu2O(s)

(h) Reagent : Na2CO3(aq) Condition : room temperature For CH3CH2COOH , carbon dioxide gas is liberated. For CH3CH2COOCH3, no visible reaction. 2 CH3CH2COOH + Na2CO3(aq) 2CH3CH2COO-Na+ + CO2(g) + H2O(g)

33