The Chemistry of Natural Waters Essay Example

Atomic Absorption concentration of calcium and magnesium. The Chemtrek lab manual's section C and D were followed for conducting the EDTA titration.

After analyzing the hardness of water, I utilized Calcium carbonate to soften it. The Chemtrek lab manual (1) provides detailed explanations of these procedures. Graph 1 displays the results for Ca2+ and Mg2+ concentrations, with corresponding Light Absorbance values for each. The data was collected at Hamilton Hall (7), where the Ca2+ concentration measured 31.17mg/L with a Light absorbance of 0.247021, while the Mg2+ concentration was 21.50mg/L with a Light absorbance of 0.

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tags includes various measurements at different locations: 5255 Bigler Hall has a measurement of 8.47 mg/L, while 47.06 mg/L was measured at another location. At 6691 University Towers, the measurement was 9.44mg/L. All measurements are presented with their respective numerical values and units of measurement.

355922.54mg/L 0.5481 Heritage Oaks (10) 23.25mg/L 0.184116.

Using an Atomic Absorption Spectrophotometer, the ion concentration in the sample was determined by comparing the resulting values to calibration graphs. These graphs, shown on the following page, were utilized to calculate each ion's concentration based on its light absorbance using Equation 1 and Equation 2 (with a value of 124.93 for the latter). The measured concentration was found to be 99mg/L0.4276.

The following equation is expressed using mathematical notation: 2470 + 1633 ? 31.02 mg/L ? 62.094 - 3.192 = 21.

Chart 1 and Chart 2 show a concentration of 47mg/L of magnesium and calcium ions, respectively. To facilitate comparison, the concentrations were converted to parts per million using Equation 3: 31.17mg/L *1l/1000g of water=31.17mg/1000g=31.17 parts per million. Table 2 displays the measured concentrations of Ca2+

and Mg2+ at Hamilton Hall, with Ca2+ measuring 31.17 parts per million.

The levels of ppm in various locations are indicated as follows: 17ppm at 21, 50ppm at Bigler Hall(8), 47.06ppm at 27, 88ppm at University Towers(9), and 44.88ppm at 22.

The combined value of 54ppm, 10ppm, 23ppm, 25ppm, and 16.99ppm for Heritage Oaks were used to determine the water's total hardness, calculated using equation 4(3): ((31.17ppmCa2+)*2.

The total hardness for Hamilton Hall is 166.5ppm, calculated by adding 5ppm CaCO3 to 21.50ppm Mg2+ multiplied by 4.12ppm CaCO3. The total hardness for Bigler Hall is 232ppm, as listed in Table 3.Results for the EDTA titration yielded the following levels of total hardness (in parts per million): Hamilton Hall (240ppm), Bigler Hall (480ppm), University Towers (310ppm), and Heritage Oaks (200ppm). The values were obtained by serial titration as demonstrated in the case of Hamilton Hall water (12 mL) using Equation 4: "Molarity of EDTA*Volume of EDTA=Molarity of Ca2+*Volume of Ca2+ 2*10^-4M*12=X=.0024M." From here, the value was converted to parts per million using Equation 5: ".0024moles/liter*100gCaCO3/1moleCaCO3*1000mg/g=240mg/L 240mg/L*1L/1000g=240mg/1000g=240ppm". Lastly, the conversion was made into grains per gallon via Equation 6: "240 ppm*1grain per gallon/17."

The equation 4 was utilized to calculate the molarity of Ca2+ ions in water after adding a softener and cat ion exchange resin. The hardness values obtained were unexpected, contrary to the hypothesis that the water on-campus would be softer due to a better budget for Penn State University. Additionally, 1ppm is equivalent to 14.035 grains/gallon.

Upon comparing the water on and off campus, it was discovered that Hamilton Hall's water wasn't necessarily softer than the latter. However, University towers' water was found to be less soft compared

to Heritage Oaks'. Interestingly, Heritage Oaks, which is situated off campus, has the softest water of all. This observation suggests that there may be a difference in their respective sources of water (5). The difference in water hardness could possibly be attributed to the use of different water sources in these areas. Additionally, it's noteworthy that Heritage Oaks is located near Wal-Mart, leading to speculations that its source of water is distinct.

The accuracy of my AA values was excellent at plus or minus one percent due to the use of a machine for calculations. Comparatively, the EDTA test suffered from human error resulting in a larger degree of variance. In addition to identifying calcium and magnesium ions, it also detects dissolved metals (6). The estimated precision is around plus or minus eight percent with the corresponding relative harnesses as presented (2).

The water in Hamilton Hall, Bigler Hall, and University Towers is classified as hard, while Heritage Oaks water is moderately hard. The high mineral content of the water may cause skin irritation in residents who use the washing machines, particularly those in Bigler and Hamilton Hall. This is due to the formation of a "soap curd" on the skin, which inhibits the return of normal acidity to the skin (4).

Based on my findings, the location of the water on or off campus did not significantly impact the hardness of the water. Rather, the source of the water was the determining factor. Specifically, water from Heritage Oaks had a softer supply compared to Hamilton Hall, Bigler Hall, and University Towers.
References: 1) Chemtrek: Thompson, Steven S.; Prentice Hall: Engelwood Cliffs, New Jersey, 1990 2) "Hardness and

Water Quality" http://water.nr.

The website state.ky.us/ww/ramp/rmhard.htm provides information on water hardness. Additionally, the website home. discusses the same topic.

Visit t-online.de/home/hydrobio.hw/twharte.htm to learn about the effects of hard water on corrosion and mineral scale caused by the presence of calcium and magnesium.

The text states that Fox's book "Healthy Water" is a part of research conducted on the topic. The research is available at edu/~eqc/hard1.htm and was done in Portsmouth, NH. Additionally, "The Beginner FAQ" can be found at faq.thekrib.com/begin-chem. All of this information is contained within HTML paragraph tags.The text within the reads "html."