Final Report
Exercise 1
CHEM 181 DL1 Determination of Water Hardness Using a Titrator
Because our calculations came out to 333.2ppm for the water hardness I would classify the water as very hard. Anything above 180 ppm is very hard water.
1. Based on the analysis of your local water, would you classif y its hardness as sof t, moderate, hard, or very hard? Explain your answer.
8oz x 8 oz =64 oz x 29.57mL= 1892mL=1.9Lx333.2mg/L=632.7mg
2. Approximately how much calcium would you ingest by drinking eight 8-oz glasses of your local water? Hint: 1 oz (f luid ounce) = 29.57 mL.
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Data Table 1: EDTA Titration Volume
8oz x 8 oz =64 oz x 29.57mL= 1892mL=1.9Lx333.2mg/L=632.7mg
3. Assume an average minimum daily requirement for calcium is 1,150 mg. Calculate what percentage of your daily requirements could be met by drinking 1.0 L of your local water.
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Data Table 2: Water Hardness
Trial Initial EDTA Volume (mL)
1
2
3
Trial Final EDTA Volume (mL)
1
2
3
Average Volume of EDTA Used (mL)
Trial Total Volume EDTA Used (mL)
1
2
3
10
11
13
7.5
6.5
10
2.5
4.5
3
3.33
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Average Volume of EDTA Used (mL)
Concentration Ca Ions Per Liter of Water (mol/L)
Average Volume of EDTA Used (mL)
Water Hardness (ppm CaCO )
2+
3.33 0.00333
3
3.33 333.2