cohols
have OH hydroxyl functionalgroup 9 methylpropan 2 01
H É on primary R2 Kotalcohol
secondary R2 Éomit fatty
OH Hz
i alcohol 110 H 20 a alcohol 30
9 Butan I 01 H3CHzCHzCH2OH Cg Butan 2 01 CH3CH2CHOH Hz
dehydrationof alcohols
we can eliminate water from an alcohol to produce an alkene
use alcohol made from fermentation ofplants means they are sustainable
normally alkenes are sourcedfrom crude oil which is non renewable
alkenes mainlyusedto make polymers which can be usedto make plastics
reaction involves use of acidcatalyst either sulfuric acid H2504 or
hosphoric acid HzPoa
e.gl canson caHa H2O ethanol ethene t water
elimination mechanism formed
m ii n
ediate ci ithene
H H2O Ht
gangsta
b
dehydration of non
yprimaryalcohols Htreformed act as a
catalyst
can lead to 2 different alkenes
e.gl
É doublebond can be formed either side
H og ftp.ii
ntj of the carbon that had the OH group
chief
conducted via distillation
dehydration of alcohol produces an impureproduct
distillation can help to separate useful alkene fromimpuritie
separates chemical by boiling point
further separationand purification may be needed
9191911 p funnel can help
of dryingagent afterwards removesany water remaining
makingcyclohexane
ipsmeapdejrgi.si layhifnanolusing distillation separation andpurificationtechniques
add conc sulfuric phosphoricacidand cyclohexaneol into a roundbottomed flas
add several anti bumpinggranules to prevent bubbles from forming
use heating mantle to warm reactants up to 830C b p ofcyclonexanol
don't use a Bunsenburner to heat ascyclohexaneol is flammable
chemicals with b p c830C will evaporate entercondensercool down and
ndense back into a liquid
condenser has cold water runningthrough the wall
productcollected in a vessel will still have small amounts of impurities
Uch as unreactedcyclonexanol and water
step 2 Separation
addproductsfrom step 1 into separatingfunnel add water todissolve
solubleimpuritiesand create an aqueous solution
Toplayer Impurecyclohexane
Bottom layer Aqueous layer containing water soluble impurities
remove stopper and drain aqueous layer off
step3 Purification
take impurecyclohexane from step2 and to a roundbottomed flask
add anhydrousCacia calciumchloride as a dehydratingagent will remove
myaqueous substances still remaining
invert flask and leave for 20 30minutes
have OH hydroxyl functionalgroup 9 methylpropan 2 01
H É on primary R2 Kotalcohol
secondary R2 Éomit fatty
OH Hz
i alcohol 110 H 20 a alcohol 30
9 Butan I 01 H3CHzCHzCH2OH Cg Butan 2 01 CH3CH2CHOH Hz
dehydrationof alcohols
we can eliminate water from an alcohol to produce an alkene
use alcohol made from fermentation ofplants means they are sustainable
normally alkenes are sourcedfrom crude oil which is non renewable
alkenes mainlyusedto make polymers which can be usedto make plastics
reaction involves use of acidcatalyst either sulfuric acid H2504 or
hosphoric acid HzPoa
e.gl canson caHa H2O ethanol ethene t water
elimination mechanism formed
m ii n
ediate ci ithene
H H2O Ht
gangsta
b
dehydration of non
yprimaryalcohols Htreformed act as a
catalyst
can lead to 2 different alkenes
e.gl
É doublebond can be formed either side
H og ftp.ii
ntj of the carbon that had the OH group
chief
conducted via distillation
dehydration of alcohol produces an impureproduct
distillation can help to separate useful alkene fromimpuritie
separates chemical by boiling point
further separationand purification may be needed
9191911 p funnel can help
of dryingagent afterwards removesany water remaining
makingcyclohexane
ipsmeapdejrgi.si layhifnanolusing distillation separation andpurificationtechniques
add conc sulfuric phosphoricacidand cyclohexaneol into a roundbottomed flas
add several anti bumpinggranules to prevent bubbles from forming
use heating mantle to warm reactants up to 830C b p ofcyclonexanol
don't use a Bunsenburner to heat ascyclohexaneol is flammable
chemicals with b p c830C will evaporate entercondensercool down and
ndense back into a liquid
condenser has cold water runningthrough the wall
productcollected in a vessel will still have small amounts of impurities
Uch as unreactedcyclonexanol and water
step 2 Separation
addproductsfrom step 1 into separatingfunnel add water todissolve
solubleimpuritiesand create an aqueous solution
Toplayer Impurecyclohexane
Bottom layer Aqueous layer containing water soluble impurities
remove stopper and drain aqueous layer off
step3 Purification
take impurecyclohexane from step2 and to a roundbottomed flask
add anhydrousCacia calciumchloride as a dehydratingagent will remove
myaqueous substances still remaining
invert flask and leave for 20 30minutes
