The Humberview Science Department Date__________________
SCH 3U0
The Little Lake Disaster
Normal rainwater is naturally acidic with a pH of 5.6. This acidity of rain often contributes to the pH of lakes being slightly acidic sometimes with a pH around 6. Unfortunately, however, a lake in southern Ontario has recently been polluted by a Hydrochloric acid spill. A tanker truck was travelling north on highway 400 toward Sudbury on its way to an ore refining centre in northern Ontario. Biologists are now concerned about the flora and fauna of the lake as many organisms especially juvenile aquatic organisms cannot survive below a pH of around 3.5 – 4. This is also a very small and busy lake utilized by many people in the community. It would be a tragedy if it was not repaired to its original state.
The biologists have now turned to you, the chemical lab intern, for help. They need you to determine, accurately, the new pH of the lake. Unfortunately the budget does not have space to buy simple pH meters that would provide results in a matter of seconds so you will need to titrate the lake water, a very tedious process. Since you are an intern you will not be getting paid for your work but you wish to make a good impression. They also needs some suggestions of strategies to neutralise the lake based on the type of acid spill and the biotic and abiotic factors present in this particular ecosystem. Your task is to put together a formal report that communicates the results of your tests as well as suggestions for strategies. You will need to do some research to help you. Therefore, you will need to document all of the resources you used. You will want to know the minimum pH allowing the most vulnerable species to survive as well as the how the substrate (bottom rock/sediment) of the lake will help combat the problem. The report is due ASAP as the ecosystem now stands in peril.
If you do a good job, you might just get hired on...