alcohols and halogenoalkanes

8/11/2019 Alcohols and Halogenoalkanes

1/26

1. A student reacted 8.72 g of bromobutane with an excess of OH

. The student produced4.28 g of butan--o!.

"n this reaction the h#droxide ion acts as a nuc!eophi!e.

$i% &hat name is gi'en to this t#pe of reaction(

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$ii% +xp!ain the term nucleophile.

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)*

$iii% Out!ine the mechanism for this reaction.

,how cur!# arrows and re!e'ant dipo!es.

)4*

)Tota! mars*

2. +thano!/ 02H1OH/ is manufactured on a !arge sca!e for a wide range of uses such as

a!coho!ic drins/ as an industria! so!'ent and as a raw materia! for the s#nthesis ofman# organic compounds.

+thano!/ 02H1OH/ is manufactured on a !arge sca!e b# two methods

3 ermentation/ using #east/ of sugars/ such as g!ucose/ 0H2O.

0H2O$a5% 202H1OH$a5% 6 20O2$g%

The ethano! is then disti!!ed off.

3 H#dration of ethene/ 02H4/ with steam in the presence of an acid cata!#st.

02H4$g% 6 H2O$g% 02H1OH$g%


2/26

0ompare the sustainabi!it# of these methods of manufacturing ethano! in terms of

3 a'ai!abi!it# of starting materia!s and energ# re5uirements

3 atom econom#.

"n #our answer/ #ou shou!d mae c!ear how the atom econom# of the processes !inswith chemica! theor#.

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3/26

3. "n the !aborator#/ ethano! can be oxidised with acidified potassium dichromate$"%.

$a% The ethano! can be oxidised to form either ethana!/ 0H90HO $Fig. 1%/ or

ethanoic acid/ 0H90OOH $Fig. 2%.

1 1 0

1 0 0

9 0

8 0

7 0

6 0

5 0

4 0

3 0

2 0

1 0

0

1 0

e t h a n o !a n d a c i d i f i e dp o t a s s i u md i c h r o m a t e $ " %

w a t e r b a t ha t : ; 0

w a t e r i n

w a t e r o u t

d i s t i ! ! a t e

i c e - w a t e r m i x t u r e

h e a t

w a t e r i n

e t h a n o !a n d a c i d i f i e dp o t a s s i u md i c h r o m a t e $ " %

w a t e r o u t

Fig. 1 Fig. 2

The boi!ing points of ethano!/ ethana! and ethanoic acid are gi'en in the tab!ebe!ow.

0H90H2OH 0H90HO 0H90OOH

boiling point / C 8 2 8


4/26

$ii% wh# the organic product is !ie!# to be ethanoic acid if the apparatus shownin Fig. 2 is used.

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)2*

$b% &rite a ba!anced e5uation for the oxidation of ethano! to ethanoic acid.


5/26

5. $a% =ropan-2-o! can be formed b# the h#dration of an a!ene in the presence of acata!#st.

$i% ,uggest a suitab!e cata!#st for this reaction.

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$ii% This is an e!ectrophi!ic addition reaction. &hat is meant b# the termelectrophile(

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$b% A mechanism for the reaction in $a% is shown be!ow.

0 H 9

H 0 H00 0

H

6

6

0 H 9

H 0 H0

H

H

O

H H

H Hs t e p 2s t e p 1 s t e p 3

0 H H90 H 9

H 0 H 6 6

6

H

H

0

H

H

O

H

$i% Add >cur!# arrows? to the mechanism to show the mo'ement of e!ectronpairs in steps 1/ 2and 3.

)9*

$ii% ,uggest/ with a reason/ the ro!e of the H6.

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)Tota! mars*

6. =ropan-2-o! is f!ammab!e and readi!# burns.

&rite a ba!anced e5uation for the comp!ete combustion of propan-2-o!.

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)Tota! 2 mars*


6/26

7. our possib!e structura! isomers of 04H:O are a!coho!s. Two are shown be!ow.

H H H H

H H H H

H 0 0 0 0 O H

H H O H H

H

HHHH

H 0 0 0 0

butan--o! butan-2-o!

$i% @raw the other two structura! isomers of 04H:O that are a!coho!s

isomer isomer 2

)2*

$ii% ame isomer . ...............................................................................................

)*

)Tota! 9 mars*


7/26

8. Butan-2-o! can be deh#drated to produce a mixture of three a!enes each with amo!ecu!ar formu!a 04H8.

@raw the disp!a#ed formu!a for each of the three a!enes.

)Tota! 9 mars*

9. $a% 0#c!ohexane can be con'erted into c#c!ohexene 'ia a three-stage s#nthesis.

s t a g e c o m p o u n d A

s t a g e 2 s t a g e 9

O H

0 l 2

cyclohexne cyclohexnol cyclohexene

$i% "n stage / c#c!ohexane reacts with ch!orine to form the organic product/compound A.

,how the structure of compound A.

)*


8/26

$ii% ,tage 9 in'o!'es the deh#dration of an a!coho!.

,tate a suitab!e reagent for deh#drating an a!coho!.

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)*

$iii% &rite a ba!anced e5uation for the deh#dration of c#c!ohexano!/ 0HOH.

)*

$b% The reaction in stage is difficu!t to contro!. One other possib!e ch!orinatedproduct is /4-dich!oroc#c!ohexane.This is shown be!ow.

s t a g e c o m p o u n d !

c o m p o u n da n dC "

s t a g e 2 s t a g e 9

0 l

0 l

0 l

2

cyclohexne 1#4$%ichlo&ocyclohexne

/4-@ich!oroc#c!ohexane reacts in the same wa# as compound Ain stages2 and 9.

$i% ,uggest the structure of compound !.

)*


9/26

$ii% Two c#c!ic a!enes/ Cand "are formed in stage 9. Cand "are structura!isomers. ,uggest the structures of Cand ".

)2*

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1'. +thano! and g!#cero! $propane-/2/9-trio!% are both produced industria!!# on a !argesca!e.

+thano! is manufactured b# both fermentation and the h#dration of ethene.

C!#cero! is produced as a b#-product of soap manufacture.

H

H

e t h n o l

0 HH

0 O HH

H

H

g l y c e & o l

0 O HH

0 O HH

0 O HH

The re!ati'e!# !ow 'o!ati!it# of a!coho!s such as ethano! can be exp!ained b# theexistence of intermo!ecu!ar bonds.


10/26

$i% +xp!ain what is meant b# the terms

low volatility/ ....................................................................................................

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intermolecular bonds ......................................................................................

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)2*

$ii% On the ethano! mo!ecu!es be!ow/ !abe! an# re!e'ant dipo!es/ show theintermo!ecu!ar bond formed and state the t#pe of intermo!ecu!ar bond.

H

H

HH 0

0 O

H

H

H

H

HH

0

0

HO

H

t#pe of intermo!ecu!ar bond ...............................................

)9*

$iii% C!#cero! forms the same t#pe of intermo!ecu!ar bonds as ethano!. =redict/ with areason/ whether the boi!ing point of g!#cero! wi!! be higher or !ower than that ofethano!.

The boi!ing point of g!#cero! wi!! be ................... than that of ethano! because

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)Tota! mars*


11/26

11. This 5uestion is about the ha!ogenoa!ane 2-ch!orobutane.

2-0h!orobutane reacts with aOH/ but the products are dependent on the so!'entused.

H

0 0H

H

H

H

H

0 0

0 l

H

H

H

O H $ a 5 % O H $ e t h a n o ! i c %

a ! c o h o ! A a m i x t u r e o f t h r e e a ! e n e s

/ a n d! C "

2-0h!orobutane reacts with OH

in a5ueous conditions to produce a!coho! A.

$i% "dentif# a!coho! A.

)*

$ii% @escribe/ with the aid of cur!# arrows/ the mo'ement of the e!ectrons in themechanism. ,how an# re!e'ant dipo!es/ !one pairs of e!ectrons and the products.

)4*

)Tota! 1 mars*

12. $a% "n the presence of a suitab!e cata!#st/ c#c!ohexano! reacts with compound(.

The organic product is shown in the e5uation be!ow.

O H + + H 2OO

C

O

co m p o un d Y

organ ic p rod uct


12/26

$i% ,tate a suitab!ecata!#st. ..................................................................................

)*

$ii% "dentif# compound(.

)*

$b% 0#c!ohexano! can a!so be oxidised to form c#c!ohexanone.

$i% ,tate a suitab!e oxidising agent for this reaction.

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$ii% &rite a ba!anced e5uation for the oxidation of c#c!ohexano! toc#c!ohexanone.


13/26

$i'% &hen 00s are exposed to strong u!tra'io!et radiation in the upper atmosphere/homo!#tic fission taes p!ace to produce free radica!s.

+xp!ain what is meant b# the term homolyticfission.

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)2*

$'% ,uggest which bond is most !ie!# to be broen when 090lis exposed to

u!tra'io!et radiation. +xp!ain #our answer.

bond ................................................................................................................

reason .............................................................................................................

)*

$'i% "dentif# the twofree radica!s most !ie!# to be formed when 090lis exposed to

u!tra'io!et radiation.

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)2*

)Tota! 8 mars*

14. +thano!/ 02H1OH/ can be produced b# the fermentation of g!ucose/ 0H2O.

&rite a ba!anced e5uation for the fermentation of g!ucose.

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)Tota! 2 mars*


14/26

15. +thano! has a re!ati'e!# high boi!ing point. This can be exp!ained in terms ofintermo!ecu!ar h#drogen bonds.

@raw a second mo!ecu!e of ethano! a!ongside the one drawn be!ow and show how ah#drogen bond cou!d be formed. 0!ear!# show an# re!e'ant dipo!es and !one pairs of

e!ectrons.

OH

0 H 2 0 H 9

)Tota! 9 mars*

16. =ropane/ 09H8/ is used in the reaction se5uence shown be!ow.

H9

0 0 H2

0 H9

H9

0 0 H2

0 H2

0 lr e a c t i o n 1

0 E u ' ! i g h tl2

A

H9

0 0 H 0 H2

C

)

"

H9

0 0 H2

0 H2

O Hr e a c t i o n 2

a 5 u e o u s O H E h e a t

r e a c t i o n 3 e t h a n o ! i cO H E h e a t

!

H9

0 0 H

O H

0 H9

r e a c t i o n 4p o ! # m e r i s a t i o n

$a% The reaction se5uence shows se'era! important reaction mechanisms. ,e!ectfrom reactions 1to 4/ the reaction that shows

$i% free radica! substitution/ reaction ..........

)*

$ii% e!ectrophi!ic addition/ reaction . .........

)*

$iii% e!imination/ reaction ..........

)*


15/26

$b% "n reaction 2/ the a5ueous OH

acts as a nuc!eophi!e.

$i% ,tate what is meant b# the term nucleophile.

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)*

$ii% 0omp!ete/ with the aid of cur!# arrows/ the mechanism in'o!'ed in reaction 2.,how an# re!e'ant dipo!es.

H90 0H2 0H2 0l H90 0H2 0H2 OH + ..........

OH

)4*

$c% 0ompounds !and "are structura! isomers of each other.

$i% ,tate what is meant b# the term structural isomers.

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)2*

$ii% @raw the se!eta! formu!ae of compounds !and ".

0ompound ! 0ompound "

)2*


16/26

$d% 0ompound Ccan be po!#merised to form compound ).

$i% ,tate the t#pe of po!#merisation. ............................................................

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$ii% ame compound ). ...............................................................................

)*

$iii% @raw a section of compound ). ,how tworepeat units.

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)Tota! 1 mars*

17. Acro!ein/ 0H2FF0H0HO/ and acr#!ic acid/ 0H2FF0H0OOH/ are both used in industr#

for the manufacture of p!astic resins and po!#mers. Both acro!ein and acr#!ic acid canbe made from prop-2-en--o!/ 0H2FF0H0H2OH.

$a% $i% @raw the structures of prop-2-en--o! and acro!ein. 0!ear!# disp!a# thefunctiona! groups in each compound.

p&op$2$en$1$ol c&olein

)2*

$ii% ame the functiona! group common to bothprop-2-en--o! and acro!ein.

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17/26

$b% =rop-2-en--o! can be oxidised to form either acro!ein or acr#!ic acid.

$i% "dentif# a suitab!e oxidising mixture.

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)2*

$ii% &rite a ba!anced e5uation for the oxidation of prop-2-en--o! into acro!ein.


18/26

19. "n this 5uestion/ one mar is a'ai!ab!e for the 5ua!it# of spe!!ing/ punctuation andgrammar.

The rates of h#dro!#sis of ch!oroethane/ bromoethane and iodoethane are different.

@escribe how #ou wou!d monitor the reaction rates.

+xp!ain wh# ch!oroethane/ bromoethane and iodoethane react at different rates.


19/26

21. $a% There are four structura! isomers of 04H:O that are a!coho!s. One of the isomers

has been drawn for #ou.

0omp!ete the tab!e be!ow to show the other structura! isomers.

0H

H

H

0

H H O H

H H H

0 0 H

b*tn$1$ol isomer 1 isomer 2 isomer 3

)9*

$b% Butan--o! is oxidised b# an acidified so!ution of potassium dichromate$"% toform a carbox#!ic acid.

$i% ,tate the co!our change that #ou wou!d see.

0o!our changes from IIIIIII.........I to IIII..II..........

)*

$ii% &rite a ba!anced e5uation for this oxidation of butan--o! to form acarbox#!ic acid.


20/26

$c% Butan--o! reacts with hot concentrated su!phuric acid to form compound !.

$i% 0ompound !has an empirica! formu!a of 0H2and a re!ati'e mo!ecu!ar

mass of 1.


21/26

22. $a% &rite an e5uation for the combustion of ethano!.

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)2*

$b% "n this 5uestion/ one mar is a'ai!ab!e for the 5ua!it# of written communication.

@escribe/ with the aid of e5uations/ the industria! manufacture of ethano! fromg!ucose/ 0H2O/ and from ethene/ 02H4. ame each t#pe of reaction and state

a!! essentia! conditions.

uture supp!ies of ethano! are !ie!# to come from g!ucose rather than fromethene. +xp!ain wh#.

)G*

Jua!it# of &ritten 0ommunication )*

)Tota! 2 mars*

23. This 5uestion is about the compounds A$Fbe!ow.

$a% Answer the fo!!owing 5uestions b# referring to the compounds A$F.


22/26

$i% &hat is the mo!ecu!ar formu!a of compound "(

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$ii% &hat is the empirica! formu!a of compound C(

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$iii% &hich two compounds are structura! isomers of each other(

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$i'% &hich two compounds are cis-transisomers of each other(

...................................................... and ..................................................

)*

$b% 0ompound )can be deh#drated to form compound A. 0omp!ete a ba!ancede5uation for this reaction.

H H

H

H

H

H

H

H

O H

0 0 0 0

H

)*

$c% 0ompound Ccan be deh#drated to form a new compound/ +/ with the mo!ecu!arformu!a/ 04H. ,uggest a structura! formu!a and a name for +.

name ...............................................................................................................)2*

)Tota! 7 mars*


23/26

24. Ha!ogenoa!anes/ such as -ch!orobutane/ are h#dro!#sed with hot a5ueous a!a!i/

OH

$a5%/ to form a!coho!s.

$a% @escribe/ with the aid of cur!# arrows/ the mechanism of the h#dro!#sis of -

ch!orobutane with OH

$a5% ions to produce butan--o!. ,how an# re!e'ant !onepairs of e!ectrons and dipo!es.

0 H 0 H 0 H 0 H 0 H 0 H

H

0

H

0 l

H

0

H

O H 6 . . . . . . . . . . . . . . . . . . .9 92 22 2

)4*

$b% Another ha!ogenoa!ane/ ,/ has a re!ati'e mo!ecu!ar mass of 27 and has thefo!!owing composition b# mass0/ 97.8K H/ .9K 0l/ 11.GK.

$i% ,how that the empirica! formu!a of compound ,is 02H20l.

)2*

$ii% @educe the mo!ecu!ar formu!a of compound ,.

)*

$iii% 0ompound ,can a!so be h#dro!#sed with hot a5ueous a!a!i to formbutane-/9-dio!. @raw the structure of butane-/9-dio!

)*


24/26

$i'% @educe the structure of compound ,.

)*

)Tota! G mars*

25. La'andu!o!/ 0:H8O/ is a fragrant oi! which is found in !a'ender. The structura! and the

se!eta! formu!ae of !a'andu!o! are shown be!ow.

0 H

0 H

H H

H

H H0

0

0

00

0O H

H 0

H 0

9

2

9

9

s t & * c t * & l - o & . * l

2

O H

s / e l e t l - o & . * l

$a% $i% "dentif# twodifferent functiona! groups in !a'andu!o!.

.................................................. and ......................................................

)2*

$ii% &h# does !a'andu!o! notha'e cis-transisomerism(

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$b% La'andu!o!/ 0:H8O/ a!so reacts with bromine to form a saturated organic

product.

,tate what #ou wou!d see in this reaction and deduce the mo!ecu!ar formu!a ofthe organic product.

obser'ation .....................................................................................................

)*

mo!ecu!ar formu!a ...........................................................................................

)2*


25/26

$c% La'andu!o! cou!d be con'erted into an ester 0/ which is a!so found in !a'ender oi!.

O

O

0

0 H 9

ester 0

,tate a reagent and a cata!#st that cou!d be used to form ester 0from !a'andu!o!.

reagent ............................................................................................................)*

cata!#st ............................................................................................................

)*

$d% La'andu!oi can be oxidised to produce either compound(or compound .

O

0

! a ' a n d u ! o !

0 H O

c o m p o u n d (

: 0 H O

0 O O H

c o m p o u n d

: 20 H O

: 80 H O

$i% &rite a ba!anced e5uation for the oxidation of !a'andu!o! to producecompound .


26/26

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)2*

$ii% An infra-red spectrum of either compound(or compound was obtained

and was found to contain an absorption between 8:

71: cm

.Howe'er/ there was no broad absorption between 21:: 99:: cm

.

B# referring to #our Data Sheet/ use this information to deduce whether theinfra-red spectrum was of compound(or of compound . ,how #ourreasoning.

The infra-red spectrum was of compound ............ because ..................

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)2*

)Tota! 2 mars*

alcohols and halogenoalkanes

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