A regional council manages a mixed land-use catchment that includes a horticulture district (fertilisers), an old galvanised-roof industrial estate (stormwater runoff), and a freshwater wetland that drains into a river used for irrigation and recreation.
After several weeks of heavy rain, residents report a fishy odour and algal growth downstream of the wetland. The council collects water samples from three sites on the same day:
Field measurements show that turbidity is highest at Site B. The council laboratory can test for ions using several options: ion-selective electrodes (ISE), colorimetric test kits, ion chromatography (IC), and atomic absorption spectroscopy (AAS). The council also keeps a record of guideline trigger values for ecosystem protection: nitrate (as \(\mathrm{NO_3^-}\)) 0.50 mg L\(^{-1}\), phosphate (as \(\mathrm{PO_4^{3-}}\)) 0.050 mg L\(^{-1}\), and dissolved zinc (as \(\mathrm{Zn^{2+}}\)) 0.030 mg L\(^{-1}\).
The following results are obtained (all concentrations in mg L\(^{-1}\)):
| Site | \(\mathrm{NO_3^-}\) | \(\mathrm{PO_4^{3-}}\) | \(\mathrm{Zn^{2+}}\) |
|---|---|---|---|
| A | 0.18 | 0.012 | 0.006 |
| B | 0.62 | 0.081 | 0.028 |
| C | 0.44 | 0.060 | 0.041 |
The council must decide whether to introduce an ongoing monitoring program and what it should include.
Using the data provided, identify which site(s) exceed the guideline trigger value for each ion, and state one environmental risk associated with elevated levels of each ion in this catchment.
Marking your answer...
This may take a few seconds
Sign up for free to see your full marking breakdown and personalised study recommendations.
Create Free Account Log inThis is a free HSC HSC Chemistry practice question worth 4 marks, testing your understanding of Analyse the need for monitoring the environment. It falls under Analysis of Inorganic Substances in Module 8: Module 8: Applying Chemical Ideas. Submit your answer above to receive instant AI-powered marking and personalised feedback.
The identification and analysis of chemicals is of immense importance in scientific research, medicine, environmental management, quality control, mining and many other fields. Students investigate a range of methods used to identify and measure quantities of chemicals. They investigate and process data involving the identification and quantification of ions present in aqueous solutions. This is particularly important because of the impact of adverse water quality on the environment. Students deduce or confirm the structure and identity of organic compounds by interpreting data from qualitative tests of chemical reactivity and determining structural information using proton and carbon-13 nuclear magnetic resonance (NMR) spectroscopy.
Inquiry question: How are the ions present in the environment identified and measured?
analyse the need for monitoring the environment
StudyPulse has thousands of HSC Chemistry questions with full AI feedback, mark breakdowns, progress tracking, and study notes across every Content Point point including Analyse the need for monitoring the environment.
