Year 12 students went to learn and perform various analytical tests on water samples in order to develop their analytical skills through a fieldtrip activity. This excursion was held on 8 May 2014 in a science institution, LIPI (Lembaga Ilmu Pengetahuan Indonesia) Bandung.
The aim of this fieldtrip is based on the HSC Chemistry Syllabus (NSW Board of Studies) that requires students to perform a first-hand investigation on water quality.
During this excursion, students were divided into four groups of six or seven, and they will be in rotation to perform four different water quality tests, which include the followings:
- The heavy metal concentration using AAS (Atomic Absorption Spectroscopy). By preparing standard solution series to obtain the calibration graph, the concentration of the desired heavy metal can be determined precisely or accurately through the absorbance of the sample. High concentration of heavy metal such as lead, cadmium and mercury may lead to serious health problems, thus the presence of these metal ions in water needs to be monitored
- Dissolved Oxygen (DO) using Winkler Method. This is done by titrating a manganese solution against in iodide stabilized thiosulfate solution and the endpoint is indicated by a color change. High DO is essential for sustainable life of water organisms
- Phosphate concentration using Spectrophotometry. Similar to AAS, this method also involves preparing of standard solution series for the calibration graph. The phosphate concentration in water needs monitoring as it may cause algae bloom or eutriphication, that can lead to decreasing DO
- TDS (Total Dissolved Solids) using gravimetric analysis through evaporation and filtration. This is related to the amount of dissolved ions present in water, which is an important indicator for water quality to show its degree of contamination, thus how it affects the ecological balance
Year 12 Chemistry Teacher