Seawater Composition and Salinity :: Tides and Salinity

Using the decanted supernatant solution from the precipitation experiment, a wire loop was dip into the solution. This loop was stuck in the flame from a Bunsen Burner and heated until a flame appeared. The presence of a bright yellow flame confirmed that Na+ was in attendance. Using a cobalt glass as a filter, the loop was examined and a violet flame was present, showing that K+ was also in the supernatant solution.Testing for NH +This test was carried out utilize the original solution to avoid contamination of ammonium salts from the other procedures. 0.1M NH4CL and DI water were added to a large soundly on the micro drop tray beforehand drops of 6M NaOH were added. A piece of red litmus paper was put on top of the well and covered with a watch glass. The appearance of an unmarked blue color, a direct result of the release of NH3 gas, on the paper confirmed the existence of NH4+. The experiment was repeated using seawater instead of the 0.1MNH4CL and DI water combination.Quant itativePre-Gravimetric Set UpTest tubes were obtained and labeled using a bl according to which test the sample was intended for Barium) and what prescience the sample was obtained at or bottom).All the test tubes were put in a beaker andan oven at 110C for half an hour to dry. Once dry th removed and allowed to cool on a test tube rack, as Figure 1 Test tube rack with test tubes Figure 1, before being weighed and their weights recSilver Halides Gravimetric AnalysisThe tests tubes labeled Halides Top and Halides Bottom were taken and 1mL of seawater was added to each. The test tubes were then weighed and their new weights recorded, before 6M Nitric sexually transmitted disease (HNO3) was added to each to acidify it. 0.1M Silver Nitrate (AgNO3) was introduced, causing a white come to form. The solution was stirred with a glass rod and centrifuges for approximately a quarter of an hour. Once complete,another series of drops of 0.1M AgNO3 were added to ensure complete precipitation and the solution was recentrifuged for several minutes. The supernatant solution was decanted into a wast container and DI water was mixed into the precipitate to clean it. The solution was centrifuged, supernatant decanted, and rinsed with DI water once more before being centrifuged and the aqueous solution decanted for a final time. The test tubes were then returned to the beaker and place back into the oven to dry for a week.