Water Hardness

Our AP Chemistry class went to Jean Lafitte park to explore and collect several species of plants and take samples of water at different locations. At each site, we collected at least 50 mL of water in three different cups. The difference in the sites was that they were each at different parts of the marsh so we could find if the hardness was affected by its location. After collecting all the samples we needed, we headed back to the lab and began our testing. To begin testing, we put 50 mL of each sample into individual beakers and tested them separately to compare. Next, we filled a burette pipette with 25 mL of EDTA solution and sat it above the beaker. Then, we added 10 mL of buffer to each sample, then we added 5 drops of indicator that made the solution turn a slight purple. Next, we began to allow the burette to slowly drip out into the beaker and we observed how many drops it took to change the solution color to blue. The more drops it took, the harder the water sample was. It wound up coming out that the hardness of water didn’t change a lot by the location of the water.