Practical work (including IA & Group 4 Project)
Introduction
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Practical work is an important component of IB chemistry. Approximately 25% of your total course time should be devoted to the practical scheme of work (40 hours at SL and 60 hours at HL). This includes the ten hours devoted to the Individual Scientific Investigation which makes up 20% of the final assessment mark under the separate heading ' Internal Assessment' with the External examinations providing the remaining 80%. Practical skills are also examined to a small extent in Section A of the externally assessed Paper 3. The 40 or 60 hours devoted to the practical scheme of work also includes ten hours spent on the Group 4 Project, although this is not assessed.
Much of the practical work will likely involve experiments in a school laboratory. However practical activities can be interpreted quite liberally. For example, a well-planned visit (as opposed to a 'tourist' visit) to a university research laboratory or industrial site such as a power station or sewage works, virtual labs or molecular modelling can also be included. Similarly, data obtained from secondary sources or simulation experiments rather than hands-on practical work is also acceptable.
One of the great strengths of the IB practical programme is that there are no 'set' experiments or investigations that you must undertake. However there are some mandatory areas listed under the 'Applications and Skills' sections for some sub-topics in the Guide. For example, you must perform a titration and also determine the molar mass of an unknown gas etc., but the precise ways in which these are done is left to either your teacher or perhaps even you, if you are encouraged to plan your own method by your teacher. All IB Diploma chemistry teachers are completely free to design their own practical programme for their own students The great strength of this is that a good teacher will design their practical programme so that it integrates fully into good chemistry teaching.
Why do practical work?
It is worth considering why practical work is so important. Ultimately, of course, chemistry is an experimental science and the whole of chemistry is based on observations. Some of the reasons are:
- to re-enforce the theory
- to develop theory from practical observations
- to learn specific techniques
- to gain confidence in manipulative skills
- to develop an appreciation of the benefits and limitations of scientific methodology
- to address the IB assessment criteria (only for the Individual Scientific Investigation)
- to have fun
The last one is important. The more you enjoy your chemistry the more you will succeed. Remember that only the ten hour Individual Scientific Investigation will be assessed, so, for much of the practical work, you do not have to worry about any form of assessment leading to your final grade.
The four components of the practical scheme of work
1. The individual scientific Investigation (10 hours)
This is the part that counts towards the final assessment. A separate section Internal Assessment covers this in detail.
2. The Group 4 project (10 hours)
This is a compulsory part of the programme but is not assessed so, provided you have done the Group 4 Project, it plays no part in your final assessment.
3. Coverage of the mandatory areas
There are several mandated areas which you must cover, either by hands-on laboratory experiments or by simulations etc. These mandatory areas are listed at the foot of this page.
4. Other good practicals
Your teacher will give you some other good laboratory experiments (practicals). These might be to reinforce the theory or to give you practical experience of particular techniques, such as reflux, chromatography or filtration under reduced pressure. Like practicals under the mandatory heading, these will build up your confidence and experience in preparation for your Individual Scientific Investigation.
The total time for components 3 and 4 will be 20 hours at Standard Level and 40 hours at Higher Level. In the teachers section on Practical scheme of work there are full details of about 36 laboratory experiments that cover these two components. These provide background details, instructions on how to carry out the practical and questions to enhance your understanding of the underlying chemistry. They are all listed under Mandatory laboratory components and Other good practicals or you can click directly on the relevant link in the list below. Although they are written for teachers they contain worksheets for students, I have given you access to all these pages so that you can refer to those that your teachers chooses for you. Although the practicals as such are not assessed, remember that Section A of Paper 3 contains about six marks devoted to practical techniques. You can read about this and do some practice example on Experimental work questions under Paper 3.
Practicals covering mandatory areas
Mandatory practical areas
I've listed below all the mandatory practical areas which you are required to cover during your course. Although there are eleven different areas listed on the syllabus, you can see by the way that I have grouped them together that some of them are essentially the same and there are basically a total of seven areas for Standard Level and eight areas for Higher Level.
The common seven areas are: quantitative determination of empirical formula, quantitative determination of the molar mass of a gas, titration involving indicators and a pH meter, the construction of 3-D models, the use of a calorimeter, reaction kinetics and the use of voltaic cells. The eighth area, for Higher Level, only is replacement reactions.
Topic 1.2. The obtaining and use of experimental data for deriving empirical formulas from reactions involving mass changes.
- Topic 1.3. Obtaining and the use of experimental values to calculate the molar mass of a gas from the ideal gas equation.
- Topic 1.3. Use of the experimental method of titration to calculate the concentration of a solution by reference to a standard solution. Topic 8.2. Candidates should have experience of acid-base titrations with different indicators. Topic 8.3. Students should be familiar with the use of a pH meter and universal indicator.
- Topic 5.1. A calorimetric experiment for an enthalpy of reaction should be covered and the results evaluated.
- Topic 6.1. Investigation of rates of reaction experimentally and evaluation of the results.
- Topic 9.2. Performance of laboratory experiments involving a typical voltaic cell using two metal/metal-ion half-cells.
- Topic 10.1. Construction of 3D models (real or virtual) of organic molecules.
- Topic 15.1. Perform lab experiments which could include single replacement reactions in aqueous solutions. (either here or 19.1) Topic 19.1. Perform lab experiments which could include single replacement reactions in aqueous solutions.