Mandatory laboratory components
Background
There are no specific experiments or practicals that all students must perform. Apart from the ten hours for the Individual Scientific Investigation and the ten hours for the Group 4 project, teachers are free to devise their own practical programme to cover the remaining 20 hours (SL) or 40 hours (HL) of the allocated time for practical activities.
However the subject guide does list eleven different areas in the Applications and Skills sections where experimental procedures are required to be covered so it makes sense to devise some practicals to cover these eleven areas. The actual experiments used to cover these mandatory areas will vary from school to school. For each of the areas I have suggested possible experiments that could be used and given full practical details. Remember that questions can be asked on these mandatory areas in Section A of Paper 3 in the external examinations.
Required laboratory components
- Topic 1.2. The obtaining and use of experimental data for deriving empirical formulas from reactions involving mass changes.
This can be covered using Determining the formula of magnesium oxide .
- Topic 1.3. Obtaining and the use of experimental values to calculate the molar mass of a gas from the ideal gas equation.
This can be covered using Determining the Mr of an unknown gas .
- 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 1.3 and Topics 8.2 and Topic 8.3 can be covered using any of:
A traditional acid-base titration
A green acid-base practical
Analysis of aspirin tablets
Percentage of CaCO3 in egg shells
Titrations with a pH meter - Topic 1.3 Instead of an acid-base titration this can also be covered by a redox titration
e.g. Redox titration with KMnO4
or Determination of vitamin C content . - Topic 5.1. A calorimetric experiment for an enthalpy of reaction should be covered and the results evaluated.
This can be covered using Enthalpy changes - Topic 6.1. Investigation of rates of reaction experimentally and evaluation of the results.
This can be covered by using any of:
Reaction rates
Rate dependent factors
Determining Ea for a reaction (Higher Level only)
Acid catalysed iodination of propanone (Higher Level only) - Topic 9.2. Performance of laboratory experiments involving a typical voltaic cell using two metal/metal-ion half-cells.
This can be covered by using Voltaic cells. - Topic 10.1. Construction of 3D models (real or virtual) of organic molecules.
This can be covered by using 3-D modelling of organic compounds
- 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.
This can be covered by using
Enthalpy changes or Voltaic cells
In fact although there are eleven different areas listed 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.