7173Detailed Notse - Production of Materials

7/25/2019 7173Detailed Notse - Production of Materials

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Claudia Cox

2014

Production of Materials Summary

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Sunowers are pretty.


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Fossil fuels provide both energy

and raw materials such asethylene, for the production of

other substances

Identify the industrial source of ethylene from the crackingof some of the fractions from the rening of petroleum

Cracking allows oil reneries to increase the output of high-demand productssuch as ethylene by breaking high molecular weight petroleum fractions intolower molecular weight substances.

Steam cracking Catalytic cracking

Used for longer chains Shorter chains (!-"# C$s%

&igher temperatures (')C% *ower temperatures (!)C%

+naerobic +naerobic

Uses hot metal coils with steam andC," as an inert dilatant

Uses eolite (crystalline porousaluminosilicates% catalysts

*ower pressure &igher pressure

C&"#(g% #C "(g% C/&0(g% &"(g% C!&/"(g% C &""(g%C"(g% C/&0(g%

Petroleum is a comple1 mi1ture of natural gas and crude oil2 containing bothalkanes and alkenes.

Identify that ethylene, because of the high reactivity of itsdouble bond, is readily transformed into many usefulproducts

3thene is the most 4ersatile and widely-used raw materials used in thepetrochemical industry2 due to the high electron density associated in thedouble bond which allows it to be transformed into many useful products. 5hismakes ethylene more unstable than alkanes2 and allows it to react readily withelectronegati4e elements such as chlorine and other halogens.

3thylene can be hydrated to form ethanol or o1idised with an +g catalyst toform ethylene o1ide and then reacted with dilute acid to form ethylene glycol

(antifreee%. 3thylene can be con4erted with a CuCl" catalyst to formchloroethene (the monomer for P6C% or polymerised into polyethylene.

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Structure and !roperties of "thylene

7 8ember of alkene homologousgroup

7 Simplest unsaturatedhydrocarbon7 *ow melting point9boiling point

(gas at "!)C% due to non-polarity and low molecularweight (only weak dispersionforces present%

7 :nsoluble in water

Identify that ethylene serves as a monomer from whichpolymers are made

+ monomer is a small unit2 which can be combined with other monomers toform polymers. Polymers are long chains of macro-molecules (usually of highmolecular weight% consisting of repeating sub-units called monomers.

:n order to form a polymer2 a monomer re;uires either a double bond or areacti4e functional group at both ends.

Identify polyethylene as an addition polymer and e#plain the

meaning of this term+n addition polymer is a polymer formed without the loss of a small molecule2by opening up of a double bond.

Polyethylene is an addition polymer2 as the double bond in ethylene opens upand


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Used in clingwrap @ plastic bags Used in garbage bins2 plasticutensils @ toys

Signicant chainbranching and air

holes as se4eralalkyl groupsbranch of duringpolymerisation

,rderly array

5here are three stages in the polymerisation of ethylene to form polyethyleneAinitiation2 propagation and termination. +s the ethylene is heated in the

presence of a catalyst (such as an organic pero1ide initiator for *BP3 or 5iCl/9(C&/-C&"%/+l for &BP3% the double bonds are brokenA aD C&"EC&" a-C& "-C&"D. +s the reaction proceeds2 the polyethylene chain lengthens (propagation%Aa-C&"-C&"D (C&"EC&"%1 a-(C& "-C&"%1D. =inally two acti4ated chainsrandomly collide to form a stable polyethylene polymerA a-(C&"-C&"%1 D a-(C&"-C&"%yD a-(C& "-C&"%1y-a.

Since2 the termination stage is completely random polyethylene polymer chainscome in 4arying lengths and molecular weights2 although there is an a4eragemolecular weight of #0 .

Identify the following as commercially significant monomers:

-vinyl chloride

-styrene

by both their systematic and common names

!*C !olystyrene

8onomerA chloroethene 8onomerA ethyl benene

'escribe the uses of the polymers made from the above

monomers in terms of their properties2++) 1b-

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Polystyrene is made from the monomer styrene (ethyl benene%. :t is widelyused in


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"#plain what is meant by a condensation polymer+ condensation polymer is a compound formed when monomer molecules


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it is e1pensi4e and diMcult to break cellulose down into glucose that re;uires4ast ;uantities of energy. 5herefore makes the process not cost-eFecti4e.&owe4er2 using bioethanol bypasses traditional sources of petrochemicals2humanity$s need for crude oil substantially and this would hugely benet theen4ironment. 5herefore2 despite the high costs in4ol4ed2 the e4er depleting

fossil fuel reser4es will mean that e4entually cellulose-based products willbecome cost-eFecti4e. Cellulose will e4entually become a potentially suitablefuture source of energy and materials.

%se available evidence to gather and present data fromsecondary sources and analyse progress in the recent

development and use of a named biopolymer6 7his analysisshould name the specic en8yme9s- used or organism used to

synthesise the material and an evaluation of the use of potentialuse of the polymer produced related to its properties

Iiopolymers are naturally-occurring polymers made using renewable resources2usually plants and micro-organisms.

With ever depleting fossil fuel reserves, the demand for renewable alternativessuch as Biopol will increase.

!roduction Iiopol is a biopolymer formed from the monomers /-hydro1ybutyrate(/-&I% and /-hydro1y4alerate (/-&6% by fostering the growth of the bacteriaalcaligenes eutrophusin a high-glucose2 high 4aleric acid en4ironment and creatinga nutrient deciency. 5he bacterium begins to store carbon in the /-&I9/-&6 co-

polymer form. 5he polymer can then be e1tracted through hot trichloromethane.

%ses

Iiopol is suitable for many uses as it is biodegrable2 biocompatible2 renewable andchemically similar to polypropylene. Iiopol is used asA

7 Nappy linings

7 Surgical pins

7 Replacement to polypropylene plastics

'evelopments: Impact

5he production of Iiopol is currently 4ery e1pensi4e compared to petroleum-basedpolymer2 and also produces pungent waste that is diMcult to dispose of. 5hesefactors se4erely limit the use of Iiopol.

&owe4er2 eForts are being made by companies such as 8etaboli1 in order tode4elop ways to produce Iiopol in transgenic plants and genetically modied E.Coli bacteria. Bespite its current cost of production and impracticality2 furtherde4elopments such as those being made by 8etboli1 may see biopolymers such asIiopol become as e1tensi4ely used as current petroleum polymers.

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$ther resources, such asethanol, are readily available

from renewable resources suchas plants

'escribe the dehydration of ethanol to ethylene and identifythe need for a catalyst in this process and the catalyst used

C2H5OH(l) C 2H4(g)+ H2O(l)

Catalyst: The reaction must occur at 180)C, in the presence of concentrated H2SO4.Theacid is extremely hydrophilic, and sucks the water out of the compound.

'escribe the addition of water to ethylene resulting in theproduction of ethanol and identify the need for a catalyst in

this process and the catalyst used

C2H4(g)+ H2O(l C 2H5OH(l)

Catalyst Dilute H2SO4breaks the bonds within the water molecule. The catalyst isneeded to speed up the reaction to a profitable level, as the H2SO4reduces the activation

energy by providing an alternative pathway for the reaction.

'escribe and account for the many uses of ethanol as asolvent for polar and non4polar substances

3thanol possesses both a hydrophilic polar hydro1yl group and a non-polarhydrophobic alkyl chain. 3thanol$s capacity for hydrogen bonding allows it todissol4e polar substances and be miscible in water for all proportions. 5he non-polar alkyl chain can form dispersion forces with non-polar substances such asiodine and hydrocarbons. 3thanol$s sol4ent abilities are why it is used inAperfumes2 food colourings9a4orings2 cleaning agents.

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$utline the use of ethanol as a fuel and e#plain why it can becalled a renewable resource

+s with all alcohols2 ethanol can be combustedA

C2H5OH(g)+ 3O2(g) 2CO 2(g)+ 3H2O(g)

'escribe conditions under which the fermentation of sugarsis promoted

5here are se4eral reaction conditions for optimal ethanol production

. 37)C is the optimum temperature for the zymase enzyme in the yeast. Fermentation

is a exothermic process, so the temperature of the system must be monitored.

". Neutral pH

/. Yeast (for zymase enzyme) and a suitable carbohydrate source

#. Dilute C6H12O6solution (if [C2H5OH] > 15%, the yeast die)

!. Anaerobic environmentH yeast reacts with oxygen to form CO2and H2O, but not

alcohol

C6H12O6(aq)+ 6O2(g) 6H 2O(g)+6CO2(g)

Summarise the chemistry of the fermentation process

5he ymase enyme present in yeast breaks down the glucose molecule intoethanol and carbon dio1ide. 5his is called glycolysis. 5he process is complicated2comprising of se4eral reactions in se;uence. Ghen the solution reaches a !Nconcentration2 the process halts as the yeast begin to die of alcohol poisoning.

C6H12O6(aq) 2 C 2H5OH(aq)+ 2CO2(g)

'ene the molar heat of combustion of a compound and

calculate the value for ethanol from rst4hand data5he molar heat of combustion (O&% is the heat released when one mole of a fuelis burned completely2 with all reactants and products in the standard states atS*C ( atm2 "!)C%. :t is a positi4e ;uantity.

5he molar heat of combustion for ethanol is /0 k9mol.

/ssess the potential of ethanol as an alternative fuel anddiscuss the advantages and disadvantages of its use

/dvantages

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7 Renewable

7 Burns clearly, as it already possesses oxygen atoms

7 Technically CO2neutralH however, high energy cost for distillation

7 Can easily be added as a petrol extender (10%) without modifying engines7 Increasing scarcity of petroleum

7 Lower ignition temperature

7 Higher flash point

'isadvantagesA

7 Would need large quantities of agricultural land in order to grow corn or sugar caneH

this would lead to starvation as well as environmental issues such as erosion and

deforestation

7 More expensive than oil

7 Hard to distil

7 Not as energy efficientH engines would have to be 50% bigger to travel the same

distance

/ssessment Ghile ethanol pro4ides a renewable way to e1tend petrol2 itwould re;uire too much arable land to replace petrol completely. :f howe4er2ethanol could be produced from biowaste2 it would be an economically and

en4ironmentally 4iable alternati4e.

!rocess information from secondary sources to summarise theprocesses involved in the industrial production of ethanol from

sugar cane

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!rocess information from secondary sources to summarise theuse of ethanol as an alternative car fuel, evaluating the success

of current usage

Bespite the eForts of go4ernments to encourage increased ethanolconsumption2 public uptake has been slow. 5he +ustralian go4ernment hassubsidied ethanol in order to make N ethanol blends (3-% more accessible.&owe4er2 car manufacturers currently ha4e little incenti4e to produce carengines that can run higher blends or e4en N ethanol.

Since the 'L$s2 the Irailian go4ernment has subsidied ethanol in an attemptto reduce Irail$s dependence on foreign countries for oil. &owe4er2 4ast;uantities of land were needed to grow ethanol crops2 which was an economicfailure. 5oday2 now that the Irailian economy restabilised2 the con4ersion to

ethanol has been a success with around !N of cars running of pure ethanoland the rest on at least a "N blend.

+lthough it is unlikely that the world will follow in the footsteps of Irail2 ethanolis pro4ing to be a successful petrol e1tender in low concentrations.

!resent information from secondary sources by writing secondarysources by writing a balanced e=uation for the fermentation of

glucose to ethanol

C6H12O6(aq) 2 C 2H5OH(aq)+ 2CO2(g)

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$#idation4reduction reactions

are increasingly important as asource of energy

"#plain the displacement of metals from solution in terms oftransfer of electrons

Ghen metals enter solution2 they lose electrons to become positi4ely chargedcations and are o1idised H egA >n(s% >n

"(a;% "e

-

Ghen metals are displaced out of solution2 they gain elections to become

neutral metals and are reduced H egA Cu

"

(a;% "e

-

Cu

(s%

3lectrons are transferred between a metal and an metal ion.

Identify the relationship between displacement of metal ionsin solution by other meals to the relative activity of metals

/ more active metal displaces a less active metal out of solution 9ie> itis o#idised and loses electrons-6

+cti4ity SeriesA

Li K Ba Sr Ca Na Mg Al Mn Zn Cr Fe Ni Sn Pb H2Sb Cu Hg Ag Pd Pt Au

Increasing reactivity

=or e1ample2 if a piece of inc metal is placed in a copper solution2 the incdisplaces the copper out of solution as inc is the more acti4e metal. 5he incgoes into solution and is o1idisedA >n(s% >n

"(a;% "e

-. 5he Cu" cations arereduced and forms a red-brown Cu metal deposit on the inc (the blue colour ofthe solution will also decrease in intensity as the Cu"ions are remo4ed%A Cu"(a;% "e- Cu (s%. 5he o4erall e;uation is >n(s% Cu

"(a;% >n

"(a;% Cu(s%.

A(s)+ BC(aq) AC (aq)+ B(s)

/ccount for the changes in the o#idation state of species interms of their loss or gain of elections

$ 1idation

I s

& oss

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? ig

I s

@ ain

,1idation is the loss of electrons and corresponds to an increase in theo1idation state.

eduction is the gain of electrons and corresponds to a decrease in theo1idation state.

'escribe and e#plain galvanic cells in terms ofo#idationAreduction reactions

Qal4anic cells consist of two compartments2 the anode and the cathode2connected by an e1ternal and internal circuit.

$#idation occurs at the anode.

?eductionoccurs at the cathode.5he reaction at the anode releases electrons which are pushed through thee1ternal circuit to the cathode. 5he mo4ement of the electrons pro4ides an emfand 4oltage2 as chemical energy is con4erted into a electrical energy.

$utline the construction of galvanic cells and trace thedirection of electron Bow

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'ene the terms anode, cathode, electrode and electrolyteto describe galvanic cells

/node5he electrode at which o1idation occurs.

Cathode5he electrode at which reduction occurs.

"lectrode + conductor connected to the e1ternal circuit2 through whichelectrons pass through to create emf.

"lectrolyte + substance that contains free cations and anions2 and allows thetransfer of which in order to maintain electrical neutrality and complete thecircuit.

Solve problems and analyse information to calculate thepotential re=uirement of named electrochemical processes

using tables of standard potentials and half4e=uations

/$'"

C/7($'"

5he emf in a gal4anic cell must always be positive65he o1idation reaction mustbe re4ersed2 and the sign of the emf in the table must be ipped.

Gather and present information on the structure and chemistry of a lead acid

cell and evaluate it in comparison to one of the following:

-Button cell

In terms of:

-chemistry

-cost and practicality

-impact of society

-environmental impact

'ry Cell Silver $#ide 0utton Cell

'iagram

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Chemistry +nodeA outer inc casing>n(s% >n

"(a;% "e

-

CathodeA :nert graphiteelectrode2 surrounded by?Cl98n,"paste"8n,"(s% "?(a;% "e-8n",/(s% &",(l% ?&/(a;%,4erallA>n(s% "?

(a;% "8n,"(s%

>n"(a;% 8n",/(s% &",(l% "?&/(g%3lectrolyteA ?Cl9>nCl"paste

+nodeA >inc>n(s% ",&

-(a;% >n(,&% "(s% "e

-

CathodeA +g",+g",(s% &",(l% "e

- "+g (s% ",&-(a;%,4erallA>n(s% +g",(l "+g (s% ,&-(a;%3lectrolyteA R,&

6oltageA .! 6

5he cell deli4ers a 4ery constant4elocity because there is nochange in the concentration ofelectrodes and electrolytes. 5he

electrolyte is a porous barrier2which pre4ents the direct contactbetween the two electrodes andallows ions to migrate2 therebycompleting the circuit.

Cost and!racticality

+d4antagesA7 31tremely cheap7 3asy to transport due to

paste electrolyte not

li;uid7 Useful when only small

currents are needed7 Small (easy to

store9use%7 8aintains steady

4oltage

Bisad4antagesA7 ?on-rechargeable

7 Short life-span7 Cannot pro4ide highcurrents

7 Iattery may leak due toouter casing beingdissol4ed

+d4antagesA7 Practical H small9portable7 Steady 4oltage as

concentrations of electrodes

and electrolytes are 1ed

Bisad4antagesA7 ?on-rechargeable7 elati4ely e1pensi4e for a

small battery

Impact onSociety

7 Stimulated interest inbatteries andwidespread use

7 Used in common

appliances (esp torches%

7 +llowed the miniaturisationof electronics and has beenimportant in specialiedareas such as hearing aids

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"nvironmental Impact

7 Small amounts of inc isharmless howe4er2large build-up must bepre4ented as inc is ahea4y metal

7 8anganese poses asimilar problem

7 3lectrolyte paste isharmless

7 ?o highly to1ic metals thatcan harm the en4ironment.

?ememberH if a ;uestion asked for a direct comparison2 include one by linkingthe two sections.

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uclear chemistry provides a

range of materials'istinguish between stable and radioactive isotopes anddescribe the conditions under which a nucleus is unstable

?uclei are unstable whene4er they are outside of the Tone of stability$ H wherethe ratio of neutrons to protons (at most2 nApE.!A% is too high H or the atomicnumber is greater than J/ (bismuth% as no stable isotopes e1ist beyond that.

'escribe how transuranic elements are produced

Z>92

5ransuranic elements are all synthetic and all are formed by neutronbombardment of hea4y elements. 5o produce elements with higher atomicnumbers2 transuranic elements are bombarded with small high speed carbon orhelium nuclei.

eg;

5he electron emitted results from the beta-decay of a neutronA

5o accelerate particles to 4ery high speeds2 linear accelerators or cyclotrons are

used. *inear accelerators use a series of 4e9-4e currents to accelerate acharged positi4e particle. Cyclotrons not only use a series of alternating currentsbut also a strong magnetic eld to constrain the positi4e particle into a spiralpath. 5hey are much more compact and can be found in ma


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Charge " - ?il

Ioni8ation ability Qood =air Poor

!enetration Poor ("-cm inair%

=air (!m in air2"mm in

aluminium%

6ery good (se4eralcm in lead%

'eBection inelectric eld

5owards negati4eplate

5owards positi4eplate

?il

adiation can be detected in many waysA

!hotographic Film

7 Film darkens when in contact

7 Radiation reacts with silver halide crystals

7 Used inTradiation badges$ for safety purposes

Cloud chamber

7 Chamber with super saturated water/alcohol particles

7 Radiation ionizes air particles, leaving a path

7 : straight, dense tracks;K: faint zig-zag path,V: very faint tracks

@eiger4Guller tubeA

7 Radiation ionizes electrons, creating an electric current

7 Makes clicking sounds when a current runs

Identify one use of a named radioisotope in industryand in medicine

Gedicine45echnetium-''m

IndustryH ?a-"#

'escribe the way in which the above names industrial andmedical radioisotopes

Gedicine

5echnetium-''m is widely used in medicine in order to diagnose heart damageand o4er-acti4e thyroid glands. :t is highly suited to this purpose as it possessesa short half-life of 0hrs. 5his reduces the patient$s e1posure2 minimiing risk.

5echnetium-''m also emits only highly penetrati4e but low energy gamma

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radiation2 which is useful as it allows clear images with little danger of tissuedamage..

Industry

Sodium-"# can be used to detect leaks in water pipes. :f the radioisotope is

owing with the water in the pipe2 no radiation can be detected. :f there is aleak2 the ?a-"# escapes with the water and radiation can be detected and theleak found. ?a-"#$s short half-life of ! hours allows the scene to be ;uicklydecontaminated and the water safe. ?a-"#$s low cost has also led to its wide-spread use.

!rocess information from secondary sources to describe recentdiscoveries of elements

5ransuranic elements with an atomic number greater than '! are produced bythe bombardment of a hea4y nucleus with a small nucleus such as carbon.31tremely hea4y elements often ha4e 4ery short half-li4es (only a few

microseconds%2 making their presence hard to 4erify.+n element disco4ered 4ery recently is darmstadtium2 with an atomic number of. :t is produced using *ead-"J and ?ickel-0#A

Barmstadtium decays almost immediately to Barmstadtium-"J (half-life seconds%.

%se available evidence to describe benets and problemsassociated with the use of radioactive isotopes in identied

industries and medicine

0enets

7 Imaging radioisotopes such as Tc-99m reduce the cost and increase the

effectiveness of diagnosis

7 Radioisotopes with varying half-lives can be used for different purposes

7 Industrially, radioisotopes reduce cost and can effectively detect structural failings.

Co-60 can measure the thickness of metals.

!roblemsA

7 Radiation risk can cause serious tissue damage, and is carcinogenic

7 Long-term risks of using radioisotopes (such as irradiating food) are not yet known

7 Short half-lives cause transportation issues

7 Some radioisotopes are expensive

7 Potential environmental risks

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7173Detailed Notse - Production of Materials

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