You will then prepare a tutorial booklet that outlines your work and that explains how to use your results to carry out calculations to determine the amount of each of the three analytes.
You will need to describe the complete composition of each of the three matrices. To do this you will need to carry out research into the typical compositions of brass, bottled water and iron tablets. For each of the three matrices, you will need to describe each component and provide an approximate percentage or concentration. You will then need to compare your results with other learners and with your research of what the typical concentration or percentage should be.
Discuss the measures taken to ensure accuracy in determining the amount of analyte present. You will need to consider aspects of good colorimetric and volumetric practice, to include the justification of the following:
- Use of a burette and other volumetric equipment
- Choice of a specific indicator
- Colorimeter calibration
- Repeat readings
The percentage error in your calculations could be used to support your arguments.
Compare the use of secondary and primary standard solutions. You will need to define primary and secondary standards, and explain why a secondary standard must be standardised with a primary standard solution. You will then justify for your specific practical titrimetric work why the use of secondary standards was chosen in preference to primary standards.
Analysis of specific errors in each method. You will need to consider how the presence of other analytes / components in the matrices may affect the accuracy of the results. This should include a comparison of how the results from these experiments may be different from those where a technician may have made solutions of pure compounds for analysis.
You will then prepare a tutorial booklet as a reference document for the students in Africa that details all the work you have done and compares ‘primary and secondary’ titrimetric standards. Investigate quantitative analysis on the components of matrices to determine their composition