Lab 3 Determinates of Water Hardness

Determination of Water Hardness Using a Titrator Heather Crall Chemistry 1 SMT- 271044 10/17/2012 Abstract From seeing all of my results and conclusion I now see that I didn’t understand this lab very well and that its not easy when others try to help. Since I have hard water it tells me that my water flows over and through rocks and minerals, like limestone. Purpose The purpose of this lab is to become familiar with the concept of water hardness. We learn that hard water contains high levels of dissolved minerals that are in the form of metallic ions.Most of Ohio which is the state I live in either has moderately hard water or hard water. For as my town the city is moderate and the country is hard. Procedure 1) Put safety things on 2) Place the stopcock in the closed position on the end of the titrator and fill with 10 mL of EDTA solution. 3) Put a crumpled up paper towel under the titrator and allow a few drops of the solution to fall into the towel. This way it fills the ti p of the titrator then close and throw the towel away. Then place the 100 mL beaker under the setup. 4) Use the graduated cylinder to measure exactly 10 mL of tap water from your sink. ) Pour the tap water into the beaker then add 5 drops of pH 10 buffer solution. Swirl carefully the mixture in the beaker. 6) Read the volume of EDTA in the titrator and record the initial volume. Then slowly open the stopcock and add 1 drop at a time while swirling the mixture.7) Once the solution turns a pale blue-gray color turn the stopcock off then record the final volume in the titrator. 8) Repeat steps 4-7 and fill in Table 1. 9) Pour the rest of the contents down the drain Data Data Table 1: EDTA titration volume| | Initial EDTA Volume (mL)| Final EDTA Volume (mL)| Total Volume of EDTA Used (mL)| Trial 1| 9 mL| 7. mL| 1. 6 mL| Trial 2| 8 mL| 6. 6 mL| 1. 4 mL| Trial 3| 7mL| 5. 2 mL| 1. 8 mL| Average Volume of EDTA Used (mL): 1. 6 mL | Data Table 2: Water Hardness| Average Volume of EDTA Used (m L)| Concentration Ca^2+ ions per Liter of Water (mol/L)| Water Hardness (ppm CaCO3)| 1. 6 mL| 0. 015 mol/L| 1,500. 9 ppm CaCO3| Results A) Based on the analysis of your local water, would you classify its hardness as soft, moderate, hard, or very hard? Explain your answer. My water is moderately hard even though it’s the city we still have plumbing problems due to our soil and the minerals in our town.The country all has hard water so the deal with rust and bigger clogs than the city. B) Approximately how much calcium would you ingest by drinking eight 8-oz glasses of your local water? HINT: 1 oz(fluid ounces) =29. 57 mL 8oz= 236. 56 236. 56*8= 1,892. 48 mL Conclusion In conclusion it seems as though my results have come to show that I have very hard water when looking at the last graph but to have it say 1,500 tells me that my results is potentially incorrect. From what I understand it shows that the calcium carbonate is very high in my town.