"Investigative study in chemistry"
Investigative study in chemistry Sophia Cheng 3 November 2008 Investigative Study (IS) Conducted in groups of 3 to 5 students Provide students with opportunities to design and conduct an investigation with a view to solving a problem Students will learn about scientific processes and how these processes work to generate new information Aims of investigative study Students can: apply their knowledge and understanding of chemistry develop and apply various practical skills develop skills such as creativity, critical thinking, communication, problem-solving develop understanding on nature of science For learning and teaching Topic XVI in NSS Chemistry curriculum For assessment Practical related task Non-practical related task Basic Chemical Experiment Investigative Assignment Analysis Study Weighting 20% 30% 30% 20% S5 ≧1 ≧3 1 ≧1 S6 Implementation timetable of SBA Year of examination Implementation of SBA 2012 & 2013 practical related tasks investigative study non-practical related tasks 2014 and thereafter practical related tasks investigative study non-practical related tasks Before/While conducting IS, students should be guided on: How to work together in a group to develop an investigation plan and solve a problem How to define a researchable topic How to search for relevant information from various sources How to write an investigation plan How to write a laboratory report or make a poster for presentation Investigative study (20 hours) Design and conduct a first-hand investigation (a) Searching for and 3 hrs 1. Design defining questions (b) Developing an 4 hrs investigative plan 2. Process (c) Conducting the 6 hrs investigation (d) Organizing and 4 hrs 3. Report analyzing data (e) Presenting findings 3 hrs Using the Allocated Lesson Time (20 hrs) Sun Mon Tue Wed Thu Fri Sat 1 2 (a) 3 4 (a) 5 6 7 8 9 (b) 10 11 (b) 12 13 14 15 16 (b) 17 18 (c) 19 20 21 22 23 (c) 24 25 (c) 26 27 28 29 30 (c) 31 1 (c) 2 3 /(d) 4 5 6 (d) 7 8 (d) 9 10 11 12 13 (e) 14 15 (e) 16 17 18 19 20 21 22 23 24 Using post-examination school days Sun Mon Tue Wed Thu Fri Sat 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 July 1 2 3 (a) 4 5 6 (b) 7 8 9 10 (c) 11 (c) 12 (d) 13 14 (e) 15 16 17 18 19 20 21 22 Implementation schedule Pros Cons Easter, Lunar -Reserve more time for -Attendance problem New Year, teaching -Extra workload Summer -Long practical section -Extent of holiday… involvement Post -Reserve more time for -Attendance problem examination teaching -Clash with other -Long practical section projects of different subjects Normal school -Complement to teaching -Chopped practical days -No attendance problem sections -Too hectic Try-out: Making Your Own Acid-Base Indicator Tasks: 1. Extract coloured pigments from plant materials 2. Use the extract as acid-base indicator and find the concentration of alkali in oven cleaner Finding information and planning Extraction of coloured pigments Choosing suitable indicators Choosing suitable indicators Find the concentration of alkali in oven cleaner More examples Salt content of snack (a)Gravimetric method (b)Titrimetric methods: • Volhard method: back titration of Ag+ with KSCN using Fe2+ as indicator • Mohr method: titration with Ag+ using K2CrO4 as indicator Design and make: Chemical cell “Coin Cell” made by aluminium foil and This chemical cell consists coins. of 9 pairs of metal couples. Its voltage is between 2 – 2.5V. Self-heating food/drink container Getting copper from its ore CuCO3.Cu(OH)2.H2O(s) 1. To extract copper metal from a given ore sample heat H2SO4(aq) 2. To isolate product CuO(s) CuSO4(aq) 3. To calculate extraction C(s), H (g) or Town gas 2 Zn(s) or electrolysis efficiency Cu(s) 4. To calculate cost of the method Appropriateness of the Topic Does the activity address something worth learning? Is the topic socially relevant, interesting or motivating? Is the cognitive demand appropriate? Do students have the required prior knowledge and adequate skills? Are resources such as journal articles, reference books, chemicals and apparatus available? Is the time available sufficient for the activity? Are there any safety concerns? Can laboratory technicians and others help in its implementation? Your concern… 10 groups, 10 different projects Scale of investigation Laboratory safety Clash with investigation of other science subjects such as Physics Collaboration with lab tech and other teachers Discussion 1. When is the best time to implement IS? Why? 2. How will you allocate the 20 hours of IS in your teaching schedule? 3. What chemistry investigations do you think are suitable for IS? 4. How much autonomy should students have in deciding their research questions? 5. What guidelines regarding IS will you give to students? How will you guide students to finish IS on schedule? 6. How will you prepare yourself to implement IS?