chem 315 -lab 9 -synth of cyclohexene

7/25/2019 Chem 315 -Lab 9 -Synth of Cyclohexene

1/25

Experiment: Date:

Synthesis of Cyclohexene 11/5/15

Name Partners Drawer No. Course / Section

Katheryn Soto N/ !1C"E#

$15/!%&

Purpose:'he purpose of this experiment is to synthesi(e an or)anic al*ene +ia ,ehy,ration of an or)anic alcohol usin) a

stron) aci, catalyst in an E1 elimination reaction. 'he i,entity of the final pro,uct will -e confirme, +ia

measurement of the refracti+e in,ex 0 spectroscopy an, a test for the presence of ,ou-le -on,s.


2/25

Experiment: Date:




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pproach:Determine the mass of cyclohexanol rea)ent C2"1!34 -y wei)hin). Compute the mass of 5.56 Phosphoric aci,

catalyst "!P3&4. Compute the moles of each Cyclohexanol an, 5.56 "!P3&. Set up the -alance, stoichiometric

e7uation an, ,etermine the molar ratio of the rea)ents. Determine the limitin) rea)ent. Calculate the theoretical

yiel, for the synthesis. ssem-le simple ,istillation apparatus an, initiate the reaction. Distill the rea)ents at

895oC. Saturate the ,istillate with soli, so,ium chlori,e. ,, 1%6 a7ueous So,ium car-onate an, test with litmu

paper until the ,istillate is -asic p";/-lue test result4.


3/25

Experiment: Date:




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Proc H 1 #ass of Cyclohexanol 0esults Bn* No.

#aterials E7uipment#ass Cyclohexanol

#ass +ial 1!.2!5)

#ass +ial I sample !1.15&)

#ass sample !1.15&?1!.2!5 J .5!)

ial

Cyclohexanol approx.

1%m@4

Electronic

-alance L%.%%14 Calculator

Desc:

'are the -alance

Determine the mass of rea)ent in +ial.

Empty the +ial into the ,istillation flas*.

Determine the mass of the +ial.

Calculate the mass of the rea)ent.

E7uation Setup:

#ass rea)ent )4 J #ass rea)entI+ial )4 M #ass

+ial )4


4/25

Experiment: Date:




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Proc H ! #ass 56 Phosphoric aci, 0esults

#aterials E7uipment#ass 5.56 "$P3&

ol m@4 !.&m@

Density )/m@4 1.;1)/m@

6 Composition 5.56

1.&m@ 1.;1 %.55 J $.51)

ial 5.56

Phosphoric aci,

approx. !.5 m@4

Ara,uate,

cylin,er Calculator

Desc:

Calculate the mass of the rea)ent from

the +olume an, the ,ensity

E7uation Setup:

#ass J Density )/m@4 ol m@4 6 comp.

5.564


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Experiment: Date:




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Proc H $ #oles 0ea)ents 0esults

#aterials E7uipment#oles Cyclohexanol

#ass )4 .5!)

#.


6/25

Experiment: Date:




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Proc H & #olar 0atio: Synthesis of Cyclohexene

Stoichiometric >alance, E7uation Bse Structural ormulas4

#olar 0atio

1 mol Cyclohexanol 1 mol Cyclohexene 1 : 1

0eaction #echanism

1. Protonation of "y,roxyl )roup -y

stron) aci, sli)htly exothermic4

!. ormation of Car-ocation/stron)

electrophile -y loss of an "!3

molecule slow/rate ,eterminin)

step? hi)hly en,othermic4

$. "!3 acts as nucleophile -ase4 an,

a-stracts a -eta proton from the

car-ocation to form the al*ene fast

step ?exothermic4

3+erall reaction is sli)htly

en,othermic. Bn,er aci,ic

con,itions at hi)h temp.


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Experiment: Date:




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Proc H5 @imitin) 0ea)ent 0esults

#aterials E7uipment#olar 0atio

Stoichiometric 1:1

Experimental N/

3-ser+ations:

>ecause cyclohexanol is the only rea)ent

in the synthesis "$P3&only ser+es as a catalyst

an, proton ,onor in the reaction is not a true

rea)ent4 cyclohexanol is limitin) an, the molesof cyclohexanol are e7ui+alent to the theoretical

yiel, of cyclohexene.

Calculator

Desc:

Compare the -alance, stoichiometric

molar ratio for the synthesis reaction to the

experimental molar ratio

f the experimental ratio is less than the

stoichiometric ratio the rea)ent in the

numerator is limitin)

'he limitin) rea)ent ,etermine the

maximum 7uantity of pro,uct that can -e

pro,uce, in a reaction

E7uation Setup:

Cyclohexanol I "!P3& O Cyclohexene


8/25

Experiment: Date:




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Proc H 2 'heoretical iel, 0esults

#aterials E7uipment'heoretical eil,

Cyclohexanolol mol4 %.%51&5mol

Cyclohexene mol4 1

#.


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Experiment: Date:




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Proc H ; 'heoretical iel, Summary 'a-le 0esults

Desc: Cyclohexanol is the only rea)ent in the

synthesis reaction therefore the moles of

cyclohexene expecte, is e7ual to the moles of

cyclohexanol use,.

.

I 1 "!31 CyclohexeneI 1 "$P3&1 Cyclohexanol>alance,

E7uation

1.%!)/mol!.1&$)/mol92.995)/mol1%%.15)/mol#olecular


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Experiment: Date:




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Proc H Simple Distillation 0esults

#aterials E7uipment3-ser+ations:

Solution -e)an to -oil aroun, %oC. Distillation -e)an aroun, 9%oC an,

remaine, at this temperature for the ma=ority o

the ,istillation process.

Distillation was stoppe, when thetemperature rose to 95oC remaine, there

-riefly an, rapi,ly rose a-o+e 1%%oC.

5.56

Phosphoric aci,

approx. !.5 m@4 Cyclohexanol

approx. 1%m@4 'eflon -oilin)

chip ce water -ath

5%m@

Distillation flas* !5m@

recei+in) flas* Alass

funnel "ot plate San, -ath 'hermomet

er with a,apter Con,enser Distillation

hea, luminum

plate

luminumfoil

Desc:

ssem-le ,istillation apparatus.

Place approx. 1%m@ Cyclohexanol an,

approx. !.5 m@ 5.56 "!P3& into a 5%m@

,istillation flas* usin) a )lass funnel.

Swirl )ently to com-ine rea)ents.

,, -oilin) Chip

Place !5m@ recei+in) flas* in ice water

-ath >e)in water circulation

"eat mixture until ,istillation -e)ins

approx. 95?1%%oC4

Collect ,istillate until the mixture no

lon)er -u--les or when the temperature

increases rapi,ly past 1%%oC.

Do not ,istill to ,ryness.

E7uation Setup:


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Experiment: Date:




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12/25

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Proc H9 #easure p" 0esults


Bpon the a,,ition of 1%6 So,ium

Car-onate a7 to the experimental solution the

litmus test turne, -lue in,icatin) that the

solution is now -asic p";4.

Complete neutrali(ation re7uire, the

a,,ition of se+eral m@ of NaC3$

So,ium

Chlori,e 1%6 So,ium

Car-onate a7 @itmus Paper

!5m@

recei+in) flas* with

,istillate Plastic

pipet

Desc: 0emo+e !5m@ recei+in) flas* from the

,istillation apparatus

Saturate the ,istillate with NaCl -y

a,,in) small amounts an, swirlin) the flas*

)ently


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Experiment: Date:




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Proc H 1% @i7ui,/@i7ui, Extraction 0esults


'he -ottom a7ueous layer was much

lar)er than the top or)anic layer containin) the

cyclohexene pro,uct.

Neutrali(e,

,istillate

!5m@

Sepratory funnel Alass

funnel Alass

stopper

1%%m@>ea*er

5%m@

Erlenmeyer flas*

Desc:

Decant the neutrali(e, ,istillate into a

sepratory funnel usin) a )lass funnel

0emo+e )lass funnel an, stopper the

sepratory funnel

llow ,istillate to settle an, separate into

layers. Drain -ottom a7ueous layer into a

1%%m@ waste -ea*er

'hrou)h the top of the sepratory funnel

pour the or)anic layer into a clean ,ry 5%m@

Erlenmeyer flas*.

E7uation Setup:


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Experiment: Date:




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Proc H 11 Dry Pro,uct 0esults


Pro,uct chan)e, from clou,y to clear

when nhy,rous So,ium sulfate was a,,e,.

nhy,rous

So,ium Sulfate

5%m@

>ea*er with

Cyclohexene

Desc:

,, small amounts of nhy,rous

So,ium Sulfate swirlin) occasionally until the

pro,uct appears clear may re7uire 1%?15minutes to achie+e clearness4

E7uation Setup:


15/25

Experiment: Date:




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Proc H1! Simple ,istillation 0esults


Secon, ,istillation was not carrie, out a

the +olume of pro,uct synthesi(e, was too smal

an, ris*e, total e+aporation.

Drie,

Cyclohexanol 'eflon -oilin)

chip ce -ath

!5m@

Distillation flas* !5m@

recei+in) flas* Alass

funnel "ot plate San, -ath 'hermomet

er with a,apter Con,enser Distillation

hea, luminum

plate luminum

foil ial with

cap

Desc:

Clean ,ry an, reassem-le the

,istillation apparatus.

Slowly ,ecant the ,rie, pro,uct from the

5%m@ -ea*er into a !5m@ ,istillation flas*

Place the !5m@ recei+in) flas* in an ice

water -ath.

>e)in water flow throu)h the con,enser.

"eat the sample an, collect ,istillate

-etween %?2oC !?$ ,e)rees -efore an, after

the -oilin) point of the compoun,4

E7uation Setup:


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Experiment: Date:




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Proc H1$ #ass Cyclohexene 0esults

#aterials E7uipment#ass Cyclohexene

#ass +ial 1!.2!2)

#ass +ial I sample 1&.!&)

#ass sample 1&.!& M 1!.2!2 1.2!!)

Cyclohexanol Calculator Electronic

-alance L%.%%14 Alass

funnel

Desc: 'are the -alance.

Determine the mass of the empty +ial

with cap.

Dispense ,istillate into the +ial usin)

)lass funnel an, seal.

Determine the mass of the compoun, in

the +ial

E7uation Setup:

#ass rea)ent )4 J #ass rea)entI+ial )4 M #ass

+ial )4


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Experiment: Date:




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Proc H 1& Percent iel, 0esults

#aterials E7uipmentPercent eil,

Experimental iel, 2.99&1)

'heoretical iel, 1.2!!)

1.2!! / 2.99&1 4 1%% J !$.196

Calculator

Desc:

Pro+i,es a measure of efficiency for the

reaction -y comparin) the ratio of experimental

pro,uct yiel,e, an, the theoretically expecte,

pro,uct yiel,s.

E7uation Setup:


18/25

Experiment: Date:




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Proc H 15 0efracti+e in,ex 0esults Bn* No.

#aterials E7uipment 0oom temperature: !$.%oC

Cyclohexene

1stND 1.&&5!

!n,ND 1.&&5

+) ND: 1.&&55

Cyclohexene

pro,uct 'issue lcohol Dropper

--e

refractometer L

%.%%%!4

Desc:

Note an, recor, the temperature of the

room

Carefully clean the prisms of the --e

refractometer with a tissue moistene, with

alcohol.

,, a small amount of the compoun,

-etween the prisms.

Aently close the prisms.

lip the switch on the left of the

instrument up to turn on the So,ium?D lamp

an, a,=ust it into position. Bse the a,=ustment *no- at the ri)ht of

the instrument so the crosshairs intersect with

the hori(ontal ,i+i,in) line of the +isual fiel,.

,=ust the ,rum *no- at the front of the

instrument to sharpen the hori(ontal line if

chromatic a-erration occurs.

Press ,own on the switch on the left of

the instrument to ,isplay the refracti+e in,ex

scale

0ea, an, recor, the refracti+e in,ex tofour ,ecimal places.

0epeat this measurement an, recor, a

secon, rea,in).

E7uation Setup:


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Experiment: Date:




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Proc H 12 'emperature Correction actor 0esults

#aterials E7uipment0oom temp J !$.%oC

Cyclohexene

ND!%J ND

0m 'empI 0oom 'emp ? !%4 %.%%%&5

ND!% J 1.&&5 I !$?!%4 %.%%%&5

ND!% J 1.&&29

Calculator

Desc:

,=usts the measure, +alue of the

refracti+e in,ex ND4 o-taine, usin) the --e

refractometer to stan,ar, temperature of !%oC.

0efracti+e in,ex is -oth wa+elen)th an,

temperature ,epen,ent for a )i+en compoun,.

'emperature an, ,ensity are in+ersely

relate,.

Density an, the +elocity of li)ht are

in+ersely relate,.

s temperature increases ,ensity

,ecreases an, +elocity of li)ht increases.

0efracti+e in,ex ,ecreases as

temperature increases.

E7uation Setup:

0efracti+e n,ex n4 M Qthe ratio of the +elocity of

li)ht in the air to the +elocity of li)ht in the me,ium

-ein) measure,R Pa+ia pp&54

or temperatures !%oC a,, the temperature

correction factor

ND!%J ND

0m 'empI 0oom 'emp ? !%4 %.%%%&5


20/25

Experiment: Date:




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Proc H1; 0 Spectroscopy 0esults

#aterials E7uipment0 Spectral nalysis:

Saturate, l*ane C" stretch

C"!4$%%%cm?1

Bnsaturate, l*ene C" stretch $%%%cm1

C"!-en,in) a-sorption at 1&5%cm?1

0 potassium

-romi,e4 pellet chemwipe

0

Spectrometer

Desc:

Place 1?! ,rops of sample -etween ! salt

plates

Place salt plate san,wich in plate hol,er

an, inset into -eam slot of the 0 Spectrometer.

Chec* with professor to ma*e sure

-ac*)roun, has -een scanne,.

Select appropriate memory location T

or U4 Press scan -utton. #a*e sure the

num-er of scans in,icates &.

Press execute -utton.

f a-sorption ,oes not rea, properly

remo+e salt plate an, try a)ain usin) a smaller

amount of the un*nown sample.

0un an, recor, a secon, trial

Press plot -utton to pro,uce )raph.

0emo+e cell hol,er an, ,isassem-le the

apparatus. Clean the salt plate with acetone an, ,ry

with chem wipe

Place salt plates in ,esiccator to ,ry.

E7uation Setup:


21/25

Experiment: Date:




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Proc H1 Dou-le >on, 'est 0esults


Due to the small +olume of ,istillate

collecte, only the >romine in #ethlyene

Chlori,e ,ou-le -on, test was carrie, out an,

compare, with the cyclohexanol rea)ent to

+erify the presence of ,ou-le -on,s.

>romine in #ethylene Chlori,e was

re,,ish -rown in color.

@ess than 1% ,rops were use, to perform

the test as the +olume of ,istillate was so small.

r in C"!Cl!,issipate,

in,icatin) the presence of ,ou-le -on,s.

romine in

#ethylene Chlori,e

solution 1!?

Dimethyloxyethane Potassium

perman)anate

& small test

tu-es 'est tu-e

rac* & ,roppers

Desc:

Bsin) a clean ,ropper place 5 ,rops of

Cyclohexanol into two small test tu-es

Bsin) a clean ,ropper place 5 ,rops of

Cyclohexene into two small test tu-es

,, 1% ,rops of >romine in #ethylene

Chlori,e solution to one of the test tu-escontainin) Cyclohexanol.

0epeat with one of the test tu-es

containin) Cyclohexene.

f the solution -ecomes colorless the re,

is ,ischar)e, from the solution4 the ,ou-le

-on, has -een -ro*en an, replace, -y two

-romine molecules.

'o the other two test tu-es a,, approx.

%.$m@ of 1!?Dimethyloxyethane.

,, 1% ,rops of Potassium

perman)anate to each of the two test tu-es.

f a -rown precipitate appears the

cyclohexene has -een oxi,i(e, ,ou-le -on,

-ro*en4 an, con+erte, to an alcohol an,

perman)anate has -een re,uce, to man)anese

,ioxi,e.

E7uation Setup:

>r!in #ethylene Chlori,e


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Experiment: Date:




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K#n3&


23/25

Experiment: Date:




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Summary of 0esults:

'he mass of Cyclohexanol was .5! ). 'he mass of Phosphoric aci, was $.51). 'he moles of

Cyclohexanol use, were %.%51&5mol. 'he moles of Phosphoric aci, use, were %.%$21;mol. 'he molar

ratio of Cyclohexanol: Phosphoric aci, from the -alance, stoichiometric e7uation was 1:1. 'he theoretica

yiel, for the synthesis reaction was 2.99&1) of Cyclohexene an, 1.5$&$) of "!3. 'he mass of Cyclohexene

synthesi(e, was 1.2!!). 'he percent yiel, for the reaction was !$.196. 'he raw refracti+e in,ex of the

final pro,uct was 1.&&55D!$. 'he refracti+e in,ex +alue calculate, to correct for temperature was 1.&&29D

!

'he 0 spectrum o-taine, showe, the followin) principal a-sorptions: Saturate, al*ane C" stretch

$%%%cm?1 Bnsaturate, al*ene C" stretch $%%%cm?1 C"!-en,in) a-sorption at 1&5%cm?1 CJC al*ene

a-sorption at 125%cm?1

an, out of plane C" -en,in) at 1%%%?25%cm?1

. n a,,itional -roa, stron)a-sorption was shown aroun, $&%%cm?1. 'he >r!in #ethylene Chlori,e test was positi+e.


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Experiment: Date:




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nalysis Conclusions:

n the synthesis of Cyclohexene is the only rea)ent. n the synthesis reaction the role of "!P3& alon)

with heat is merely to ser+e as a source of protons for the protonation of the hy,roxyl )roup of

Cyclohexanol an, to cataly(e the reaction not to ser+e as a true rea)ent. s such Cyclohexanol is the

limitin) rea)ent the theoretical yiel, of Cyclohexene in moles was e7ual to the num-er of moles of

Cyclohexanol use, an, a maximum pro,uct yiel, of 2.99&1) of Cyclohexene an, 1.5$&$) of "!3 was

anticipate,. 'he reaction was initiate, an, simple ,istillation was carrie, out. 'he reaction mixture

was ,istille, at 9%oC an, cease, when the temperature rose rapi,ly o+er this temperature. >ecause th

reaction is an e7uili-rium reaction heatin) the mixture shifts the e7uili-rium towar,s the formation o

the al*ene pro,uct.

'he ,istillate was then neutrali(e, -y the a,,ition of an a7ueous -ase 1%6 So,ium Car-onate4 until

the p" of the mixture was +erifie, as such -y @itmus test. NaCl was then a,,e, to the ,istillate to

re,uce the solu-ility of Cyclohexene in any remainin) aci, an, water -y?pro,ucts that mi)ht ha+e

-een co?,istille,. 'his cause, the ,istillate to separate into layers with the a7ueous phase settlin) to

the -ottom of the sepratory funnel an, the less ,ense cyclohexene pro,uct risin) to the top. 'he

or)anic layer was then ,rie, with nhy,rous So,ium Sulfate to remo+e resi,ual "!3 from the

pro,uct. lthou)h careful la-oratory practices were use, throu)hout this process the +olume of

pro,uct that resulte, after these proce,ures was +ery small 1.2!!) representin) !$.196 of the

theoretical yiel,4. n the interest of conser+in) what little pro,uct remaine, the secon, ,istillation wa

not performe, as ,istillin) such a small +olume of compoun, is more li*ely result in total e+aporation

rather than a si)nificant isolation of purifie, pro,uct.

0e)ar,less 0 spectrum for the pro,uct was o-taine, an, analy(e, to ,etermine if first ,istillation

resulte, in a pro,uct that was pure enou)h to carry out the remain,er of the experiment. 'he ma=ority

of spectrum a-sorptions were foun, +isually consistent with the a-sorptions shown for a stan,ar, 0

spectrum of Cyclohexene o-taine, from the SD>S we-site. 'he spectra for the pro,uct showe, a

-roa, stron) 3" a-sorption at $&%%cm?1that was not consistent with the stan,ar, spectrum. 'his

was li*ely ,ue to resi,ual "!3 or Cyclohexanol. 'his coul, -e controlle, for -y performin) the secon,

simple ,istillation proce,ure to further purify the pro,uct.

inally the compoun, was teste, with >r!in #ethylene Chlori,e. r! ,i, not persist in,icatin) the presence of ,ou-le -on,s. 'he secon, confirmatory testwith K#n3& was not carrie, out ,ue to the small +olume of pro,uct. Some of the potential errors of

this experiment inclu,e the thermal inefficiency of the ,istillation apparatus an, errore, temperature

rea,in)s of the thermometer. Bsin) fractional ,istillation rather than multiple simple ,istillations

coul, ai, in increasin) the yiel,. ,,itionally the yiel, coul, -e maximi(e, -y the a,,ition of a

compoun, with a hi)her -oilin) point such as toluene4 to help push more of the pro,uct towar,s the

recei+in) flas*. lthou)h this a,,s an a,,itional impurity to the reaction mixture more of the ,esire,

pro,uct woul, ,istill.


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Experiment: Date:




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@iterature Summary Bn*nowns Synthesi(e, Compoun,s4

Bn*nown No.

CS No. 11%?$?

Name BPC4 Cyclohexene

Synonyms

'etrahy,ro-en(ene

#eltin) Point

oC4

@it ?1%$.5oC

Exp

@it

Exp

@it

Exp

@it

Exp

>oilin) Point

oC4

@it !.9oC

Exp

@it

Exp

@it

Exp

@it

Exp

0efracti+e n,ex nD

!%4@it 1.&&25

!%

Exp@itExp

@itExp

@itExp

Solu-ility

0el to

chem 315 -lab 9 -synth of cyclohexene

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