Standard Deviation Of The Second Water Essay

1230 Words Nov 17th, 2016 5 Pages
Buxton hall’s water had 42 ppm of CaCO3 present in all three trials conducted. The standard deviation from these tests was 0. Kroger water had a 46.2 ppm of CaCO3 in the first trial, 50 ppm in the second trial, and 43.2 ppm in the third trial. The standard deviation of the second water sample was 3.41. Crystal Geyser water had a 16.42 ppm of CaCO3 in the first trial, 21 ppm in the second trial, and 22 ppm in the third trial. The standard deviation of the third sample was 2.97.

According to the table provided, 0-50 CaCO3 ppm is considered soft water, 51-150 CaCO3 ppm is moderately hard water, 151-300 CaCO3 ppm is hard water, and anything above 300 is very hard water. All of the water that was sampled during this experiment is considered soft water. The Crystal Geyser water was the softest out of all of the samples and the Kroger water was the hardest.

During this lab, there were many errors that could have taken place that would have affected our calculations. Even though we were using a burette to deliver EDTA to our water samples, we could have misread the amount that was titrated or assumed whole numbers rather than decimal points. We could have also titrated more than necessary considering the color change was not instantaneous. As we performed more titrations we became more diligent with how much we added at a time which could have led to our last titrations being more accurate than our firsts. Another error that was possible was contaminated. We used the…

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