Question

0.1001 Sample Volume ViEDTA VI EDTA 0135L 02して'8_1 O1241L AVEDTA ,moles EDTA moles EDTA Moles EDTA Molesca2. Sample [Ca2* moles Ca moles Ca2 mg CaCO3 mg CaCO3 Sample Hardness USGS Hardness Classification mg CaCO3 Accepted Hardness % Error Chemicals, Materials and Equipment Eriochrome Black T indicator solution (0.4 g/L) Disodium EDTA solution (0.0100 M) Ammonia/Ammonium Chloride Buffer (pH 10) Magneisum Chloride Solution (1x103 M) Saturated CaSO4 solutions previously prepared and equilibrated to 60°C and 90°0C hot/stir plate 60°C and 90°C water baths 50 mL buret 5 mL volumetric pipette 1mL serological pipette 1mL beral pipette Calculations Part 1: Measuring Water Hardness - Complete the following and add the information to the data table provided 1. Determine the moles of EDTA used to titrate each sample. 2. Assuming that Ca2 was the only source of hardness in your water sample, determine the [Ca"] for each water sample. Assuming that calcium carbonate was the only source of Ca2+ in your samples, determine the hardness in mg of CaCOs/L and rate it according to the USGS classification. 3. Your instructor will provide you with the accepted value of the hardness for the school's tap water. Based on this value calculate your percent error 4.

Answer 1

6,0 0,04969レ edta Ve edta 0.02291レ 0 0 362yL edta 0.0281 = 0,00105 Moles 1-22 edta. Moba (A2さ 36.2 040.01 23 07 [ 鬥| 0,9 oy y 9.oy 0100 0' 368 Cata 368-3624xloo 368 1.5ス2 Scanned with CamScanner 36. 38 CS