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Experiment #10 The Chemistry of Natural Waters Lab Report Jake Shoemaker Group: 11/5/10 Chemistry 111 Section 103
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Introduction: Water hardness is defined as a measure of the amount of calcium and magnesium salts dissolved in water4. Hard water is water that contains large amounts of dissolved calcium and magnesium cations, and soft water is water that little or none of the cations10. The hardness of water is important because it affects numerous aspects of our life. Water hardness has an effect on the way water tastes, it creates problems with plumbing and industries, and the water hardness has an effect on cleaning/washing10. The calcium and Magnesium that exist in the water do not taint it in any way. The hardness of water does, however, affect the way the water tastes, but different individuals have different opinions on which type tastes better. The problem of water hardness in the use of industrial water boilers/plumbing systems10 is that the water evaporates leaving behind rocklike deposits consisting mostly of calcite crystals 10. This is a problem because the calcite crystals build up and clogs pipes, blocks jet engines, etc. and is very expensive and difficult to remove, if removable at all10. Problems similar to these can be found everywhere that large volumes of natural waters are used to undergo the industry’s processes3. In washing, when hard water is used to wash away soap the soap anions react with the calcium and magnesium cations to produce a greasy scum3. There are various methods in measuring water hardness. EDTA
(ethylenediaminetetraacetic acid) titration is one method that is commonly used. EDTA titration is a chelating agent3. A chelating agent is a substance whose molecules can form several bonds
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to a single cation3. An indicator is added to the sample to be tested that turns red if magnesium is present in the sample. EDTA is added after and first reacts with the calcium cations then the magnesium
Shoemaker 1
Introduction: Water hardness is defined as a measure of the amount of calcium and magnesium salts dissolved in water4. Hard water is water that contains large amounts of dissolved calcium and magnesium cations, and soft water is water that little or none of the cations10. The hardness of water is important because it affects numerous aspects of our life. Water hardness has an effect on the way water tastes, it creates problems with plumbing and industries, and the water hardness has an effect on cleaning/washing10. The calcium and Magnesium that exist in the water do not taint it in any way. The hardness of water does, however, affect the way the water tastes, but different individuals have different opinions on which type tastes better. The problem of water hardness in the use of industrial water boilers/plumbing systems10 is that the water evaporates leaving behind rocklike deposits consisting mostly of calcite crystals 10. This is a problem because the calcite crystals build up and clogs pipes, blocks jet engines, etc. and is very expensive and difficult to remove, if removable at all10. Problems similar to these can be found everywhere that large volumes of natural waters are used to undergo the industry’s processes3. In washing, when hard water is used to wash away soap the soap anions react with the calcium and magnesium cations to produce a greasy scum3. There are various methods in measuring water hardness. EDTA
(ethylenediaminetetraacetic acid) titration is one method that is commonly used. EDTA titration is a chelating agent3. A chelating agent is a substance whose molecules can form several bonds
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to a single cation3. An indicator is added to the sample to be tested that turns red if magnesium is present in the sample. EDTA is added after and first reacts with the calcium cations then the magnesium
Cited: 1. Azoulay, Arik. "Comparison of the Mineral Content of Tap Water and Bottled Waters." Journal of General International Medicine (2001). Pub Med Central. Society of General International Medicine, 2001. Web. 6 Nov. 2010. . 2. Azoulay, Arik. "Comparison of the Mineral Content of Tap Water and Bottled Waters." Journal of General Medicine 16.3 (2004): 1-8. Wiley Online Library. 9 June 2004. Web. 6 Nov. 2010. 3. Fairfax County Water Authority. "Explanation of Water Hardness." NAV. Web. 09 Nov. 2010. . 4. "Glossary: Fluoride." GreenFacts - Facts on Health and the Environment. 2005. Web. 09 Nov. 2010. . 5. Muzidial, David, and Ian Smiley. "Brita Filter for Homebrewing." Brewery. 4 Mar. 1996. Web. 09 Nov. 2010. . 6. Oram, Brian. "Drinking Water Hard Water Hardness Calcium Magnesium Scale Stained Laundry." Drinking Water Testing Environmental Testing Lab Water Research Center. Web. 06 Nov. 2010. . 7. Schneider, Alex. Lab notebook pages 35-59. 8. Shoemaker, Jacob. Lab notebook pages 31-35. 9. Silverberg, Sam. Lab notebook pages 38-43. 10. Thompson, Stephen. "The Chemistry of Natural Waters." PSU Chemtrek. Plymouth: Hayden-McNeil, 2011. 10-1-0-22. Print. Shoemaker 12 11. Titration, By Complexometric. "Determination of Water Hardness By Complexometric Titration Class Notes." Homepages.ius.edu. 19 Apr. 2010. Web. 06 Nov. 2010. . 12. World Health Organization. "Hardness in Drinking-water." Guidelines for Drinking-water Quality 2 (1996): 1-9. Web. 6 Nov. 2010. .