VCE CHEMISTRY, UNIT 2:
HOW ARE SUBSTANCES IN WATER MEASURED AND ANALYSED?
Our Water Sample Analysis program gives students an insight into the role of the analytical chemist in monitoring water quality, as well as addressing Key Knowledge areas of Unit 2 Chemistry. They will gain hands-on instrumentation experience in our extensive laboratory which includes Atomic Absorption, UV/Visible spectrometers as well as a Gas Chromatograph/Mass Spectrometer.
The theory underpinning each instrumental technique will be covered, as well as the operational considerations and applications. Samples for testing can be provided, or you may choose to supply your own to make the tests more relevant to your community. Standard activities include the measurement of iron, lead and copper in water, pH and conductivity. Students will gain experience in the creation and use of calibration curves, sample preparation as well as an appreciation of the sampling and analytical procedures required by regulatory bodies.
Teachers may use the program as the basis for School Assessed Coursework. Alternatively, teachers may choose to modify the program in consultation with Earth Edstaff to facilitate data collection and processing for the Practical Investigation component of Unit 2. Facility exists to measure sodium, potassium, aluminium, magnesium, calcium, silicon and zinc as well as semi-volatile organics. Soil samples can also be tested and sample collection kits provided, along with sampling guidelines.
KEY KNOWLEDGE: OUTCOME 2
Water sample analysis
• sampling protocols including equipment and sterile techniques for the analysis of water quality at various depths and locations
• the definition of a chemical contaminant and an example relevant to a selected water supply.
Measurement of solubility and concentration
• the concept of solution concentration measured with reference to moles (mol L-1) or with reference to mass or volume (g L-1, mg L-1, %(m/m), %(m/v),
%(v/v), ppm, ppb) in selected domestic, environmental, commercial or industrial applications, including unit conversions.
Analysis for salts in water
• sources of salts found in water (may include minerals, heavy metals, organo-metallic substances) and the use of electrical conductivity to determine the
salinity of water samples
• the application of colorimetry and/or UV-visible spectroscopy, including the use of a calibration curve, to determine the concentration of coloured species
(ions or complexes) in a water sample
• the application of atomic absorption spectroscopy (AAS), including the use of a calibration curve to determine the concentration of metals or metal ions in
a water sample.
KEY KNOWLEDGE: OUTCOME 3
• the characteristics of laboratory techniques of primary qualitative and quantitative data collection relevant to the investigation: sampling protocols;
gravimetric analysis, acid-base titrations and/or pH measurement; precision, accuracy, reliability and validity of data; and minimisation of experimental bias
• ethics of and concerns with research including identification and application of relevant health and safety guidelines.