- existence of water in all three states at Earth’s surface including the distribution and proportion of available drinking water
• the definition of a chemical contaminant and an example relevant to a selected water supply.
- 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 a calibration curve, to determine the concentration of metals or metal ions in a water sample (excluding details of instrument).
• 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.
• the use of solubility tables and experimental measurement of solubility in gram per 100 g of water
• the quantitative relationship between temperature and solubility of a given solid, liquid or gas in water
• the use of solubility curves as a quantitative and predictive tool in selected biological, domestic or industrial contexts