Scenario
You work in an oil refinery and have been asked to write an article for a chemisty journal outlining the importance of the industry including the range of products which can be made as a result of refining oil.
Task 1 L03.1
a) In assignment 1 you carried out a fractional distillation of synthetic crude oil in the lab and explained how this method works. In industry some of the fractions are processed further and some are cracked. Why are they cracked?
b) Briefly outline the main types of cracking, identify the main products and explain what they are used for.
c) Haloalkanes are useful starting materials for synthesis as they undergo substitution and elimination reactions. Write a free radical mechanism to show how a monosubstituted haloalkane can be made from an alkane and a halogen. Include an initiation step, at least 2 propagation steps and at least one possible termination step.
Task 2 LO 3.1
a) Draw reaction mechanisms to show the addition of hydrogen bromide to 2-methylbut-2-ene showing all the possible products.
EGK 13/7/12
ce-rt. tre main product and explain this in terms of Markovnikov's rules and m•-•x=cr szability.
.'.we an equation to show how ethene is converted to ethan-12-diol using cold octass.um permanganate in alkaline conditions.
d) Write equations to show the products of propene with hot acidified potassium dichromate.
• e) (i) Write an equation to show how an epoxide is formed when propene reacts with an peroxy acid.
(ii) What would the product be in the presence of water and an acid catalyst?
f) Alkenes also react with ozone. which is a milder oxidising agent than potassium permanganate. The intermediate ozonide is not isolated but is reduced. What can be used to reduce this intermediate and what are the products formed by this reaction.
g) Write a balanced equation for the reduction of propene with Hydrogen. Give the • reaction conditions including a possible catalyst.
Task 3 LO 3.1
a) From the sheet of monomers and polymers draw choose 3 polymers and draw 3 repeating units to show how the polymers are made up.
b) Low density polyethene(LDPE) and high density polyethene (HOPE) have different properties and are made in different ways.
Briefly outline the differences in properties between the polymers, what they are used for, how they are made and how this affects their properties.
EGK 1317/12
Task 4. LO 3.1
Research the following reactions of the alkynes. Hydration; hydrogenation, Lindlar catalyst and use of sodium in liquid ammonia. You may like to use the questions below as a guide as to what to include.
a) Write a balanced equation, reaction mechanism and reaction conditions for the hydration of alkynes. Why are they hydrated?
b) Hydrogenation of alkanes. what are the reaction conditions and why are they hydrogenated. What are the products used for.
c) What is a Lindlar catalyst? What is it used for and how does it work? What type of geometric isomer does it make and why?
d) One method of making alkenes from alkynes is to use sodium in liquid ammonia. Write a mechanism for this and explain why sodium in ammonia is used including which geometric isomer you would obtain.
e) For M3 and 03. Present your information in an appealing and creative way. This should be in a form which can be shared with your class. (e.g. as a handout, leaflet or you may put a presentation on the HNC Moodie site. Use your imagination.)
End of Tasks
Assessment feedback against targeted criteria:
General Feedback
Pass Criterion Possible Evidence* Met/Not met
L03.1 explain the reactions of alkanes.alkenes and alkynes in terms of reaction mechanisms
EGK 13/7/12
Task 1 you have outlined the reactions of alkanes including at least one reaction mechanism. Tasks 2 and 3 you have explained reactions of alkene and have included and explained reaction mechanisms of alkenes. In task 4 you have explained reactions of the alkynes and have included at least one reaction
Feedback
¦erit Criteria 1.11 identify and apply ••-etegies to find appropriate solutions •2 Select/design and apply appropriate methods/techniques M3 Present and M3 You have presented your research on the alkynes in an communicate appropriate format. appropriate findings Feedback
mechanism
Possible Evidence* M1 In task 2 you have applied your knowledge to write balanced equations, reaction mechanisms and identify the products from reactions independently.
Distinction Criteria D1 Use critical reflection to evaluate own work and justify valid conclusions D2 Take responsibility for managing and organising activities D3 Demonstrate convergent/lateral/creative thinking Feedback
Possible Evidence* D1 You have critically evaluated the way you carried out the research in task El and the way you presented this to the class.
D3 You have demonstrated creative thinking in the way you . presented your findings in task
*(please specify where evidence for meeting criteria is offered in the assignment)
• Learner Comments Provide reflection on the work you are submitting including its strengths and areas for improvement. Provide any general comments on the assessment process.
Learner Signature Date
. Polyethylene high density (HDPE) -(CH,-CH2),i- ethylene CH2=CH, rigid, translucent solid electrical insulation bottles, toys Polypropylene (PP) different grades ACHrCH(CHArr-propylene CH2=CHCH,Mack: soft, elastic solid Iesdrc: hard, strong sol id similar to LOPE carpet, upholstery oly(vinyl chlorlde) (PPVC) -(CHrCHCI),, vinyl chloride CH2=CHCI -J strong rigid solid pipes, siding, flooring Poly(vInylidene chloride) (Saran A) -(CH,CC12), vinylidene chloride CH2aCCI: dense, high-melting ol sid seat covers, films Polystyrene (PS) -(CHrCH(CeHsfin-CHeCHCelis ewe' rigid' clear scale soluble in organic solvents toys, cabinets packaging (foamed) PolyaerylonitrIle (PAN, Orion, Acrilan) -(CHs -CHCN), acrylonitri le CHeCHCN high-melting solid soluble in organic solvents rugs, blankets clothing Polytetreflumethylene (PTFE, Teflon) -(CF=-CFz).- tetraftuoroethylene CFeCF, resistant smooth solid non-stick surfaces electrical insulation Polyffnethyl methecrylate) (PMMA, Lucite, Plexiglas) -(CH, C(CNCO2CH31fr methyl methacrylate ClituC(CH3)CO2CH3 bard, transparent so„ " lighting covers, signs skylights Poly(vInyl acetate) (PVAc) -(CH, CHOCOCH3), vinyl acetate CHeCHOCOCH3 soft, sticky solid latex paints, adhesives cis-Polyisoprene natural rubber --(CHrCH.C(CH3)- CHO, isoprene CHeCH-C(CH3)=C1 t soft, sticky solid requires vulcanization for practical use (cis •i• trans) (Neoprene) -(CHrCH=CCI- CH2),,- chloroprene CH =CH-CC tough, rubbery solid synthetic rubber __1PoTychloroprene oil resistant
ITask. Choose 3 of the polymers above and draw out 3 repeating units for each.