.. esis that the water from East Halls would have been the hardest due to the size and the length of travel of the water through the large pipes, which are underground. Through testing the water samples by AA and EDTA testing, we concluded that the water from Florida was the hardest.
Next came the sample from East Halls, State College, and then the sample from Pittsburgh, PA. The following table is a summary of both tests, the AA and EDTA titration testing.Table 2 Source of Water Concentration of Ca from AA Test Absorbance Value for Ca from AA Test (at 422.7 nm) Concentration of Mg from AA Test Absorbance Value for Mg from AA Test (at 202.
5 nm) Concentration of Ca from EDTA Titration Tap in Dorm Room in East Halls 25.55 mg/L 0.429 18.75 mg/L 0.3771 140 ppm Tap from House in Pittsburgh, PA 20.29 mg/L 0.3424 6.
02 mg/L 0.154 120 ppm Tap from Hotel Room in Panama City, FL 29.1 mg/L 0.4888 29.
04 mg/L 0.5773 320 ppm We have proven that our hypothesis was wrong. This hypothesis is wrong because of the error of research. We thought since the system in the dorms would be the hardest because of the large pipes underground which would have a greater change of letting ions enter the water. However, the water from the hotel room was the hardest because for one reason it was taken from a completely different state in the United States and therefore shows that different areas have different ways to contribute tap water to citizens. The sources of the water may differ depending on what location or what the surrounding geography is like around the city (ex: ocean, river, large city). The results for the TDS testing proved that our water sample did contain ions which left a residue.By comparing it to the distilled water drop, you could plainly see that the distilled water had much less residue or ions.
Next, our outcomes were slightly different between the two different tests for our water samples. For example, in Table 2 the first test on the dorm water seems to be pretty accurate (140 ppm EDTA and 140.9 ppm AA); however, the other two samples vary between each test (120ppm EDTA and 75.4 ppm AA for the second sample and 320 ppm EDTA and 192.5 ppm AA for the third sample).
This occurred because of human error. The EDTA testing is not as accurate as the AA testing because the EDTA testing is completely done by human calculation and observation.During the titration process, there could have been contamination in the wells and/or the pipets, which we were using in the experiment. Also, the observations could have been affected by this contamination. If the color changed too quickly/slowly, some of the chemical that causes the color change could have been present/absent in value compared to what was to be present/absent in value. However, even though the tests had different quantitative values, the overall picture is accurate. They still fit into the categories in Table 1, how hard/soft they are depending on how much ions are present in the water samples.Both the two tap water samples from State College and Pittsburgh, PA were soft and the hotel room water from Florida was hard as you can see in the following table: Table 3 Source of Water Total hardness from AA test.
Total hardness from EDTA test. Tap in a dorm (East Halls) 140.9 ppm 140 ppm Tap from House in Pittsburgh, PA 75.4 ppm 120 ppm Tap from hotel room in Panama City, FL 192.5 ppm 320 ppm The last result for the experiment was the water softening agents. The results of the softening tests showed that the ion exchange resin reduce water hardness more than the baking soda.
The following table shows the difference. Table 4 Source of Water pH of Water pH of Water with Resin Beads Tap in Dorm Room in East Halls 8 5 Tap from House in Pittsburgh, PA 7 3 Tap from Hotel Room in Panama City, FL 8 4 This table shows that with the resin beads the water became more acidic.The ion exchange resin works to soften by exchanging ‘soft’ ions for ‘hard’ ions.
After both procedures with the water softening were completed, we did a EDTA titration test one the samples. Through the equation I used earlier (example equation 1), we found that the data proved the softener worked. By using the second equation (example equation 2) I found the total hardness of the water with the softener and I reported the data in Table 5 below. As you can see the baking soda did exactly what it was thought to do, it softened the sample water. Table 5 Source of Water Total hardness from EDTA test with softener. Total hardness from EDTA test without softener.Tap in a dorm (East Halls) 80 ppm 140 ppm Tap from House in Pittsburgh, PA 60 ppm 120 ppm Tap from hotel room in Panama City, FL 280 ppm 320 ppm The Baking soda agent was more effective than the resin beads.
In conclusion, our hypothesis was proven false by the experiment. The reason for the fact that the tap waters pick up many impurities in their travels from being rainwater to coming out of the faucets. However, State College’s water purification system has been lately improved which is why the water here in State College is lower than the tap water in FL. Also, due to the fact that both the water from State College and Pittsburgh, PA comes from a near by water purifying company. Since there is so many residence in the areas of where the tap water was taken, the demand for water is more than in Panama City, FL where not as many residents live there . FL water purifying company is not as close to the hotels and therefore, the water will collect more ions as it has a farther distance to travel than the waters from the dorm and the house.This is the reason that the tests in the lab gave data to support this new hypothesis: water from the tap in a residential area is less hard then areas farther away from the water purifying company.
References 1. Brown, Theodore L., H. Eugene LeMay Jr., Bruce E. Bursten.Chemistry: The Central Science.
Upper Saddle River: Prentice Hall, 2000. 2. Thompson, Stephen. PSU Version of Chemtrek: August 2000 to July 2001.Englewood Cliffs: Prentice Hall, 2000. 3. http://courses.
chem.psu.edu/chem14/water.pdf. 4. http://www.cciw.
ca/gems/atlas-gwq/gems12.htm. 5. Hardness and Water Quality.
ca/gems/atlas-gwq/gems10.htm. Additional credit is given.
.for their contributions from the dorm tap water, and the house tap water.Also, for their data given from the same lab procedure. Science Essays.