SCIENCE OCR LEVEL 2 CAMBRIDGE TECHNICAL. Cambridge TECHNICALS CHEMICAL DESIGN CERTIFICATE/DIPLOMA IN J/505/3124 LEVEL 2 UNIT 12

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1 Cambridge TECHNICALS OCR LEVEL 2 CAMBRIDGE TECHNICAL CERTIFICATE/DIPLOMA IN SCIENCE CHEMICAL DESIGN J/505/3124 LEVEL 2 UNIT 12 GUIDED LEARNING HOURS: 60 UNIT CREDIT VALUE: 10

2 CHEMICAL DESIGN J/505/3124 LEVEL 2 AIM AND PURPOSE OF THE UNIT This unit is about chemical design and innovation. Learners and teachers have scope to make choices within the unit to study different contexts depending on their interests. Learners may choose to study products that have commercial interests or may choose to specialise in looking at some innovations in the context of the careers they hope to follow. The unit looks at some chemicals that have very widespread use; washing powders, high performance car fuels and polymers, and ends with learners doing a case study in an area of interest to them. The unit lends itself to a large amount of practical work but could also be taught, relying on IT skills, with opportunities for data gathering, making presentations and using computer molecule simulation software if it is available. 2

3 Chemical Design Level 2 Unit 12 ASSESSMENT AND GRADING CRITERIA Learning Outcome (LO) Pass Merit Distinction The learner will: The assessment criteria are the pass requirements for this unit. The learner can: To achieve a merit the evidence must show that, in addition to the pass criteria, the learner is able to: To achieve a distinction the evidence must show that, in addition to the pass and merit criteria, the learner is able to: 1 Know the main components of washing powders and how they work. 2 Know how the components of car fuel are produced and why each component is important. P1 describe the main components of washing powders and explain the purpose of each component P2 perform a series of experiments to test the effectiveness of washing powders P3 describe the structure and properties of the molecules in crude oil P4 describe what happens at an oil refinery and why each process is important M1 describe the chemistry behind the action of some of the components of a washing powder M2 compare the effectiveness of washing powders under different conditions by using detailed observations and measurements M3 illustrate the molecules in crude oil using 2D and 3D formulae and link the shapes of molecules to their properties M4 explain how cracking and reforming reactions help to balance the supply and demand for crude oil fractions D1 describe the advantages of using petrol with a higher octane number and how the octane number of petrol is increased 3

4 Learning Outcome (LO) Pass Merit Distinction The learner will: The assessment criteria are the pass requirements for this unit. The learner can: To achieve a merit the evidence must show that, in addition to the pass criteria, the learner is able to: To achieve a distinction the evidence must show that, in addition to the pass and merit criteria, the learner is able to: 3 Know the properties and uses of different polymers. 4 Understand the factors which influence chemical design. P5 describe examples of different types of polymers, their importance and how their properties relate to their uses P6 perform experiments to compare the properties of polymers in the context of their suitability for a particular use P7 outline some current chemical innovations and demonstrate why they are useful or important M5 illustrate the chemical differences between the structures of a range of polymers using 2D and 3D formula M6 illustrate some current chemical innovations to demonstrate what needs these innovations meet and what further work is needed to ensure that they meet safety standards D2 explain how the structure of polymers can be modified to alter their properties, linked to examples of polymers with unusual properties D3 illustrate some current chemical innovations with a detailed explanation of the underlying chemistry and an evaluation of the development in terms of the balance between their benefits, safety and sustainability 4

5 Chemical Design Level 2 Unit 12 TEACHING CONTENT The unit content describes what has to be taught to ensure that learners are able to access the highest grade. Anything which follows an i.e. details what must be taught as part of that area of content. Anything which follows an e.g. is illustrative, it should be noted that where e.g. is used, learners must know and be able to apply relevant examples to their work though these do not need to be the same ones specified in the unit content. LO1 Know the main components of washing powders and how they work. Components of washing powders Purposes of components in washing powders (for example bleach, water softeners, surfactants/ detergents, enzymes, fluorescents) Washing powders have different actions depending on their contents (for example washing powders for colours have no bleach, biological washing powders contain enzymes) Washing powders have different actions depending on the temperatures at which they are used Advantages of washing at different temperatures Advantages and disadvantages of including bleaches in washing powders Bleaches in washing powders only become active at higher temperatures Enzymes as biological catalysts to digest protein stains (for example in terms of digestion or the lock and key model of enzyme action) Enzyme action optimised at 40-50⁰C Differences between soaps and detergents (in terms of their ingredients and action) Water softeners to reduce the amount of soap needed and to prevent scum formation in hard-water areas Head and tail model for detergents Fluorescents/optical brighteners to absorb UV and give off light to improve the appearance of white fabrics Testing effectiveness of washing powders Range of factors (for example type of washing powder, length of wash cycle, temperature, type of stain, amount of washing powder used) Control of variables Design of tests Risk assessment Repeatability of outcomes of tests Presenting data using tables and graphs Methods of comparison of outcomes Drawing conclusions Evaluating the techniques used LO2 Know how the components of car fuel are produced and why each component is important. Molecules in crude oil Names and formulae of alkanes (e.g. up to 8 carbon atoms). Trends in boiling point, viscosity and flammability of alkanes linked to their state at room temperature and pressure, and their uses (e.g. as fuels and lubricants), link between size of molecules, strength of forces between molecules and boiling points Relationships between molecular formulae, structural formulae and 3-d models of alkanes Shapes of alkanes including bond angles Processes at an oil refinery An outline of what happens at each of the main stages (no detail necessary) e.g. delivery of crude oil, fractional distillation to separate oil into fractions, cracking and reforming, blending and transport of finished fuels Relative demand for different crude oil fractions Cracking large molecules to meet demand for smaller molecules Structure of molecules from cracking reactions, including molecules with double bonds Reforming reactions to make cycloalkanes Effect of reforming on properties; forces between molecules linked to boiling point and flammability (a treatment of flash points is not required, but learners should realise that boiling points affect flammability because it is the vapour above a liquid fuel that ignites) Octane number Advantages of using petrol with a higher octane number Features of molecules that increase octane number (effect of size of molecules, branched molecules, cyclic molecules) Cracking and reforming as a means of producing molecules with higher octane numbers LO3 Know the properties and uses of different polymers Polymers and properties Names of a range of common polymers and their uses 5

6 (for example, polyethene, polypropene, PVC, PET, nylon, polyester, polystyrene) Scale of use and importance of the range of uses of polymers (e.g. data about industrial production of polymers, diversity of use, importance to most commercially produced products, packaging, waste and recycling). Structures of simple polymers using displayed formulae and 3-D representations (e.g. addition polymers such as polyethene, polypropene and PVC). Nylon and polyester as examples of polymers with a linking group Properties of polymers (for example softening temperatures, density, thermal properties, conductivity, strength, plastic and elastic properties, flexibility, behaviour at very low temperatures) The links between the uses of polymers and their properties Modifying polymers Use of modifications to change the structure and properties of polymers (for example, plasticisers, cross linking, chain length) Properties of polymers related to structure in terms of forces between chains and the movement of chains Polymers with unusual properties (for example, bullet proof, water soluble, biodegradable, heat resistant, heat shrinking polymers) Comparing polymers Carrying out practical work compare the properties of some polymers Risk assessment Collection and presentation of data Repeatability and accuracy Presenting outcomes and conclusions Evaluation LO4 Understand the factors which influence chemical design. This LO should form the basis of a case study. Research skills to collect and present information relating to a chemical innovation. How chemical innovation supports our lifestyle (for example commercial products, products for health, cosmetics, medicine, sport, the environment) Safety considerations of new products Sustainability considerations of new products The benefits of chemical innovation 6

7 Chemical Design Level 2 Unit 12 DELIVERY GUIDANCE LO1 Know the main components of washing powders and how they work. The unit could start with a survey of labels from packets of washing powder and advertisements. What claims do manufacturers make? What are the components of the washing powders? What instructions about amount of washing powder and temperature do the packets give? What different types of washing powders are available? Learners could carry out some research at home about the amount and type of washing that is done, and what views people have about the effectiveness of stain removal and the cost of the weekly wash. The teacher may then do formal teaching, with practical work, to illustrate the different ways that washing powders work, for example testing bleaches, water softeners (such as washing soda), soaps and detergents and showing fluorescence using a UV light source. Alternatively, learners could do web-based research using a structured question trail to find out about the action of the components of the washing powders. In the second part of LO1, learners can plan their own research into the effectiveness of washing powders. They will need to produce a written plan, with a risk assessment, for the tests they intend to do, and they will also need to keep a careful record of all of the measurements and results of their tests. This part of the unit may then end with the learners summarising the outcomes of their tests. LO2 Know how the components of car fuel are produced and why each component is important. It may be possible to organise a visit or a speaker for this part of the unit. Local petrol stations, garages or car sales firms may be able to talk to learners about the benefits of using different fuels in vehicles. Learners could do a video diary or a photograph trail of alkanes in their local petrol station (they will need to seek permission to take photographs due to safety concerns over ignition). There are often propane and butane canisters and lubricating oils on sale in addition to petrol and diesel. Learners may either draw or build molecules using molymod models or use computer simulation packages to build models. Some computer modelling software packages are available for free download and provide a means for learners to build molecules and export images to their written reports. There are virtual tours of petrochemical refineries available on the internet. Practical work could be carried out into viscosity and a comparison of properties of alkanes and alkenes (it is not necessary to study alkenes in detail). One context to use is to compare the contents of winter and summer blend petrol in terms of its flammability and volatility. Learners could do practical work into cracking petroleum jelly. The unit also gives opportunity for data analysis. Learners may be given or research data into properties and demand for the molecules in crude oil and present the data in different forms e.g. graphs, charts, annotated diagrams. It is important that the learners link the properties to the usefulness of the molecules as fuels at each stage. Learners may use an online search engine to find photographs of the price boards or pumps at petrol stations to show the different types of fuels available and discuss why drivers may choose to use the super fuels with higher octane numbers, even though they are more expensive. They could also look at, or produce, advertisements for the different types of fuels explaining the advantages of each type. Car manufacturers websites show typical miles per litre ratings for diesel and petrol cars which learners may compare. LO3 Know the properties and uses of different polymers A starting point for this part of the unit could be doing a survey of plastic waste (by a phototrail or diary) and then looking at plastic recycling symbols. Alternatively, learners may do a video diary or survey to show how they use polymers in a 24 hour period. The teacher may contextualise the learning e.g. focusing on polymers used in clothes, in a cafe or on a building site. Some DIY stores give free literature that could be used as a visual stimulus for learners to cut out and include in their work. Laminate worktops or flooring catalogues often give lists of properties of the materials. Practical work could look at flexibility and strength of cling film, the story behind why polyethene has replaced plasticised PVC for making cling film, behaviour of polymers when they are frozen (strips of bubble gum work well to show how polymers become brittle), breaking strength of strips of carrier bags or fibres or stretch of fibres (e.g. nylon fibres from tights). 7

8 Learners may do a web-based research task to find out about polymers with unusual properties, for example using water soluble polymers for hospital waste bags or dishwasher tablet coverings. Learners should investigate at least two factors (e.g. stretch, breaking strength, water absorbency of polymer gels used in disposable nappies). If possible, this should be contextualised (e.g. strength of different carrier bags). LO4 Understand the factors which influence chemical design. This part of the unit may either be delivered via independent project work or by a teacher-led case study. Depending on the topic chosen, there are opportunities for local visits (e.g. to local supermarkets, DIY stores, waste disposal sites, hospitals or medical centres) and for learners to make their own research tools such as question trails, questionnaires or vox pop interviews (where learners take short videos of different people answering a similar question). Possible areas for study include biodegradable packaging, nanoparticles, low solvent paints, non-animal tested cosmetics, low additive food storage, low fat food technology, synthetic sweeteners, oral contraceptives, electroplating, synthetic rubbers, dyes, fuels from chip shop fat, low toxicity and CFC-free solvents for dry cleaning, face creams and sun lotions with high SPF values, eye lash lengthening mascaras). Learners should look at two innovations, but these may be linked, for example two different developments that have been used to improve a similar type of product. 8

9 Chemical Design Level 2 Unit 12 SUGGESTED ASSESSMENT SCENARIOS AND GUIDANCE ON ASSESSMENT Criteria Assignment Scenario Assessment LO1 How do washing powders work? The learner carries out a consumer investigation of washing powders to find out how effective they are at removing stains. The assessment can be in the form of a written report or could be a series of adverts and articles for a consumer magazine along the lines of Which magazine looking at the effectiveness of washing powders. P1 Learners could use a table to present the information about the components of washing powders or could design an annotated advertisement to show the purpose of each component. M1 Learners at merit describe the science underlying each component of the washing powder. In some cases this may be about how the component removes dirt and stains or about how it improves the action of the powder (e.g. the advantages of using enzymes to enable the washing powder to be effective at lower temperatures). P2 Learners should give a clear account of how they tested the washing powder(s), in a form that another learner could follow, and should include a risk assessment. The tests should look at more than one factor. M2 Learners working at merit should present the measurements and outcomes of their tests clearly and use the outcomes to make judgements about the effectiveness of the washing powder(s). They may choose to present a summary of their findings in the form of an article or report. 9

10 Criteria Assignment Scenario Assessment LO2 What s in petrol? The learner produces a case study of fuels used for cars, showing what components are in the fuel, their functions and how they are produced. P3 Learners should show the names and structural formulae of alkanes with up to 8 carbon atoms. They may choose to produce large annotated diagrams of different types of fuel with annotated bubbles to show their contents. Learners may produce their own tables or graphs to present data about the properties of the molecules. M3 To meet the merit criteria, learners need to add to their work to show the 3-D shape of molecules, either by drawing, photographing molymod models or importing images from computer simulations. If images are pasted in from websites, the images should be accompanied by annotations to make it clear that the learner understands what the images show (e.g. by giving bond angles or describing the shape). Learners should also link the trends in properties of the molecules to the size and shape. P4 Learners may use an aerial photograph of an oil refinery and label the main stages that happen using annotations, or they may produce a flow chart. It is important that each stage is briefly explained in terms of what takes place. M4 Learners may present simple data about supply and demand for different crude oil fractions and should include a description of what happens during cracking and reforming linked to the production of fuels. D1 Learners may present images with written text (e.g. PowerPoint slides with notes) to show the advantages of higher octane fuels and should include links to how and why cracking and reforming are used to provide molecules to be blended to make vehicle fuels. 10

11 Chemical Design Level 2 Unit 12 Criteria Assignment Scenario Assessment LO3 Why are polymers important? Learners research information about polymers both using the internet and by practical activities and present their findings. The assignment may be contextualised (for example polymers for the supermarket for the kitchen for building in a hospital. Alternatively, the learner could be asked to produce a report for a company that has a commercial interest in producing polymers for a particular purpose e.g. a packaging or carrier bag manufacturer. P5 Learners may show common polymers in use (e.g. as slides or photographs) and link this to a brief description of how the properties of each polymer suit its use. M5 The learners should include diagrams of the molecules in the polymers with annotations to show how the structures differ from each other. D2 Learners should relate the properties to the structures in terms of the forces and movement between chains and discuss how polymers may be modified and the usefulness of unusual polymers. P6 Learners should present an account of some practical tests, including appropriate risk assessments, into at least two different properties of polymers. The account could take the form of a lab book or could be contextualised into a report for a company that has a commercial interest in the particular polymer. The learners need to summarise the outcomes of their practical tests in a format that makes a clear comparison to show the extent to which the properties of the polymers match their use. To meet the merit criteria it is important that learners test a range of polymers (e.g. by testing carrier bags from different supermarkets to compare their strengths). LO4 Case Study: Chemical Innovation Learners complete case studies into an area of their interest. They may choose to investigate products linked to the careers that they hope to follow at the end of the course. The actual content of the learners assignments will depend on the area chosen for their case study. P7 Learners may present information in a table, chart or presentation about a range of chemical innovations with a brief description of their usefulness and importance. M6 Learners should develop their account of two aspects of chemical innovation more fully to describe what needs are met. The learner also needs to make it clear what issues of safety and sustainability are raised by the innovation, and what further work is needed to improve its suitability and safety. D3 Learners should include a description of the science behind the innovation. They should also give an evaluation in terms of the balance between the benefits it brings and the current safety and sustainability of its prolonged use. 11

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