Achievement Task

Chemistry students at Lake Erie High School have noticed that there are fewer fish and frogs in the lake and the shore water is often choked with weeds and algae. They feel that they can and should do something to improve their environment since many people in Ontario use Lake Erie as a source of drinking water and a recreational area. They talked to their chemistry teacher Ms. Norma Clature about what they should do, and she reminded them that they had recently completed a unit directly related to this problem. They had just finished learning how to name compounds, how to predict products of reactions and write equations, and how to test for various anions and cations. In fact, the students had just completed a qualitative analysis lab where they learned how to identify ions such as sulphates, phosphates, and ammonium present in solutions (See Appendix). These ions are also found in chemical nutrients.

Ms. Clature thought that the entire chemistry class should become involved in this issue and divided the class into research teams that would each produce a complete report on the health of Lake Erie that could be used to make a presentation to town council.

1. Research all possible sources of chemical nutrients. Your research must include an inventory of the chemicals found in your house. Check the ingredients of all cleaning products, disinfectants, and drain openers.

2. For each product, make sure you list the chemicals, their common and IUPAC names, and also provide the correct formulae for the compound.

3. Once you have discovered sources of chemical nutrients in your house, check to see if local industries, farms, or sewers could be contributing to the levels of pollutants in the water and air.

Students will work in groups. Each group will investigate a different research question and test for the presence of ions whenever possible. Equations should be written for all observed chemical reactions. Some sample research questions that students could investigate are:

1. Are household chemicals the major source of nutrients in lakes and rivers? Test cleaners for the presence of ions using the analysis techniques learned in the qualitative analysis. You should then research what happens to chemicals that go down the drain and how water treatments plants remove chemicals from the water. You could also test the effluent from water treatment plants for any chemical nutrients.

2. Are industries or farms in the area responsible for pollution? Students need to collect and test water in the area of industries or farms and then research what chemicals the industry or farms use that could pollute the water.

3. What pollutants are present in local lakes and rivers and how can they be removed? Students will perform qualitative analysis tests on water samples and then determine what action should be taken to remove these from the water.

Each team should develop an excellent understanding of the nature and source of the chemical pollutants they are investigating. The maintenance of controlled experiments and data tables of observations that describe the source of the solution being tested are essential to producing valid conclusions. By keeping an accurate record of observations, teams could then determine where and what pollutants are found in local waters.

In your conclusion, you will describe possible sources of pollutants and where these pollutants are found in your area. It is important that teams thoroughly investigate all possible sources of pollutants.

You will then support these statements with experimental evidence. Observations should include chemical equations that describe any reactions that occurred. Experimental evidence from all teams will be used to describe the state of the environment to the school and town council.

Some teams will discuss not only the chemicals present in the water, but also what can and should be done to improve water quality. To do this, students should research techniques to improve water treatment plants, alternatives to any household products that contain chemical pollutants, or alternatives to cleaning industry or farm effluent.

Each team of students is responsible for creating a scientific report that includes an abstract, an introduction that summarizes their research, an outline of their research in sufficient detail to allow replication, detailed data tables, an analysis of their data that includes chemical formula and equations, and a conclusion that includes recommendations for reducing pollutants in the environment. Since these reports are the basis for a formal presentation, it is important that the scientific evidence for the conclusions be detailed and well-documented.

Members from city council, environmental organizations, etc. could be invited to class on the days that the students present their findings.