The Chemistry of Natural Waters Essay -- Science Papers

Defined in Chemtrek as â€Å"The presence of the dissolved divalent cations Ca2+ and Mg2+. . . (which) gives natural waters chemical properties†, hard water has always been a curse to both animals and man 1 . It promotes scale, the buildup of magnesium and calcium to the point where a rock-like substance forms in household and industrial pipes, disrupts natural habitats and reproductive cycles of fresh water fish, and causes many health-related problems in humans 2 . To avoid such problems, it is important to understand ways that commercial businesses and homeowners can test for hard water. This experiment examines two possible methods of testing water hardness. They include: AA spectroscopy, which measures a water sample's absorption of Ca 2+ and Mg 2+ , and EDTA titration, which uses a titration's end-point to determine the concentration of Ca 2+ and Mg 2+ present in a water source 1 . It is also important to learn about water softening, a process that removes calc ium and magnesium from water sources 3 . For this experiment, I explored water softening techniques such as divalent cation removal ion exchange and water softening with a commercial water-conditioning agent 4 . My group decided to test AA spectroscopy, EDTA titration, and water softening techniques on four natural water samples from Little Chickies Creek in Mount Joy,PA; Allegheny River in Warren, PA; Stone Valley Lake in State College, PA; and a pond on Orr Avenue in Apollo, PA because it is imperative to know about the quality of Pennsylvania's waterways. My hypothesis stated that the water from Little Chickies Creek would be the hardest because it is located by several limestone quarries, which deposit calcium and magnesium into creeks and streams 5 ... ... Prentice Hall, 2003. 5 McClintok , Michael. â€Å"A Hard Look at Soft Water.† The Washington Post 28 August 2003 : H.02. 6 â€Å"Threats to Western Pennsylvania Waterways.† Creek Connections . 13 October 2003 . 7 Van der Leeden , Frits; Troise , Fred L.; Todd, David K. The Water Encyclopedia . 2nd ed . New York : Lewis Publishers, 1990. 8 Krogman, Nick. Chemistry 14- AA Spectroscopy Calibration Data Charts. 9 Anderson , Troy . Chemistry 14-Lab Notebook, Experiment 10. p. 54-59. 10 Angiulli , Alayna . Chemistry 14-Lab Notebook, Experiment 10. p. 41-45. 11 Toms, Jarrett. Chemistry 14-Lab Notebook, Experiment 10. p. 49-54. 12 Robb, Gordon A. and James D.F. Robinson . â€Å"Acid Drainage from Mines.† The Geographical Journal March 1995: 47.