S431- Environmental Chemistry

SPRING 2010

Assignment 2

Due: February 12, 2010

1. Exactly 5 kg of fructose (C₆H₁₂O₆) were accidentally discharged into a stream saturated with oxygen from the air at 25 degrees Celsius.  How many liters of this water could be contaminated to the extent of removing all the dissolved oxygen by biodegradation?

2.  Calculate the fraction of each species (CO₂, HCO₃^- and CO₃^2-) in water that is in equilibrium with air at 25 degrees Celsius and has a pH of 9.5 

3.  Using Excel (or your favorite spreadsheet software), reconstruct Figure 3.8 (Fundamentals of Environmental Chemistry from “Environmental Chemistry’) showing the distribution of species in water as a function of pH.

4.  By next week, we should be at the point of introducing ‘water pollutants’.  Prepare a 3 minute oral introduction (use power point please!) to the ‘water pollutant’ assigned to you.  You may use any source (e.g., text, web-site, journal article, etc) but be prepared to cite some of your references if asked.  Provide some information on the sources of your pollutant to the environment, explain how it gets into the environment, and why we are concerned with it (e.g., is it toxic and, if so, how does it affect organisms).  Presentations will be made in class on February 12, 2010.  E-mail your PP presentation prior please. 

NOTE:  At this point you are not expected to be an expert on your assigned pollutant.  You merely are ‘setting the stage’ for further discussion in CHEM417 lectures and readings.  Instead of an overview, you may wish to describe an article or journal publication that sheds light on some aspect of the environmental chemistry of your “water pollutant”.