Hard+and+Soft+Water

I have ordered a sodium ion exchange resin for your project: Ms. S-Hunt

**The Removal of Hardness from Water. Spencer Bemel and Katy Fellman.** The purpose of this lab was to determine how to test calcium levels in hard water using a calcium selective electrode and to determine how much ion exchange resin is needed to remove calcium ions from water. The methods used in this lab were the creation of a standard hard water solution with 0. 007 g of calcium chloride mixed with 50 mL of distilled water and pouring 5 mL of hard water through different amounts of ion exchange resin. hard water was a clear odorless solution with the average temperature of 21.5ºC. A Vernier calcium selective electrode was then used to determine the levels of calcium in the three samples used. Various masses of ion exchange resin were used because it was hypothesized that the greater amount of ion exchange resin used the softer the water. This hypothesis was proven true for when 2.12 g of ion exchange was used with 5 mL of hard water and after filtering the calcium level was 1.6 mg/L Ca. When a smaller amount of resin, 0.79 g, was used the calcium level was 10.2 mg/L Ca. Therefore the hypothesis was proven to be correct with the amount of resin inversely proportional to the calcium levels. Key Words: Hard Water, Calcium Chloride, Calcium Selective Electrode

Figure 1: The Calcium levels of formerly hard water after being run through ion exchange resin  Figure 2: The Calcium Ion Selective Electrode during calibration media type="file" key="recording GOOD.wav" Citations: Casiday, R. (1998). //Water hardness: inorganic reactions experiment//. Unpublished manuscript, Department of Chemistry, Washinghttp://spa-chemistry.wikispaces.com/Hard+and+Soft+Waterton University, St. Louis, MO. Retrieved from// //http://www.chemistry.wustl. edu/~edudev/LabTutorials/ Water/FreshWater/hardness.html//

//"Hard Water - Soft Water." //City Collegiate //(2011): n. pag. Web. 28 Feb 2011. .// //Lower, S. (2010). //Hard water and water softening//. Unpublished manuscript, Department of Chemistry, Simon Fraser University, Vancouver, Canada.// //Retrieved from http://www.chem1.com/CQ/ hardwater.html // //Hard and soft water. (2006).// Science Reference Center//, 1-2. USGS. Water hardness and alkalinity. (2009). Retrieved from http://water.usgs.gov/owq/ hardness-alkalinity.html