Determination of Water Hardness

1052 Words5 Pages
Purpose- The purpose of this assignment is to familiarize yourself with the concept of water hardness, and to learn how to use titrator. Procedures- First, we must test the indicator. Add 8-10 drops of distilled water into a beaker. Add 1 drop of buffer solution to the distilled water in the beaker. Add a few grains of EBT indicator powder to the solution and stir with a toothpick. The solution should be a bright clear blue. If it’s not clear blue, add 1 more drop of EDTA. Wash the content of the beaker down the drain. Rinse the beaker, first with tap water and then with distilled water. Dry the beaker thoroughly with a paper towel before using it again Place a thick text book on top of the LabPaq box to use as a titrator holder. Use the test tube holder to clamp the titrator which is simply a 10-mL syringe with an affixed stop cock. Place a 100 mL beaker next to the box/book stack where it will sit under the titrator. Place a small piece of white paper under the beaker to help in the observation of color changes. Slip the clamp handle into the textbook at a level where the stop cock tip is approximately 1 – 2 cm above the top of the beaker as shown in the photo. Use an empty pipet to fill the syringe with 9 -10 ml of 0.01 M E.D.T.A. solution. Allow a few drops of the EDTA solution to drip into the beaker. This fills the tip of the titrator and removes any air bubbles from the tip. Pour the few drops of EDTA solution from the beaker down a sink or toilet drain, and then flush with lots of water. Wash the beaker well with soap and water to remove all the EDTA solution. Well rinse the beaker, first with tap water and then with distilled water. Dry the beaker thoroughly before further use. Read and record in the data table the initial volume of EDTA solution remaining in the titrator. Read from the bottom of the meniscus and try to interpolate between
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