Part B Ion-Exchange Resins by happo7


									          Active Chemistry H 2Woes

                                     Na+    Na+    Na+       Na+     Na+     Na+       Na+

                                                                   water containing
                                                                   Ca2+ and /or Fe3+

                                            Ca2+                                Fe3+

                                                       Na+       Na+

                                                                                                ?   5Na+

                        6. Find the mass of the batch precipitate.       3. Load the mixing flask or filtration
                                                                            column with the recorded amount
                          a) Measure the mass of a dry piece of
                                                                            of acidic anion ion-exchange resin.
                             filter paper and record this value
                                                                            An acidic ion-exchange resin is a
                             in your Active Chemistry log.
                                                                            polymeric material that has negative
                             Filter according to your teacher’s             sites on its surface. These negative
                             directions. Dry the precipitate                sites attract and absorb positive ions
                             on the filter paper as directed by             such as Ca2 and Mg2 , removing
                             your teacher.                                  them from water. As the water
                          b) Calculate the mass of your                     sample comes into contact with the
                             CaCO3(s) precipitate. Record                   resin beads, the Ca2 and Mg2
                                                                            ions are attracted to the negative
                             this value in the table in your
                                                                            sites, replacing the Na ions
                             Active Chemistry log.
                                                                            originally on each bead.
                        7. Test the filtrate qualitatively for
                                                                         4. Process a sample of untreated water
                           water hardness by adding some
                                                                            with the ion-exchange resin.
                           soap to it and observing whether
                           the solution is cloudy.                       5. Analyze your filtered solution
                          a) Record your results in the table               for total water hardness. For a
                                                                            quantitative analysis, follow the
                             in your Active Chemistry log.
                                                                            experimental design in Activity 3 for
                      Part B: Ion-Exchange Resins                           the analysis of total water hardness
                                                                            (Investigate, Part A). For a qualitative
                        1. Choose either the batch or                       analysis, add some soap to a portion
                           flow technique that you used                     of your water sample before and after
Dispose of the              in Activity 5.                                  the treatment with ion-exchange
materials as
directed by your        2. Create a table in your Active                    resin. Shake the solution to see if it
teacher.                                                                    becomes cloudy.
                           Chemistry log to collect all of the
Clean up your              necessary data. In addition to the               a) Record the results in the table in
workstation.               data collected for the particular                   your Active Chemistry log.
Wash your
                           method in Activity 5, you will want
hands and arms             to include the amount of resin used
thoroughly after
the activity.              and have a column for the analysis
                           of the filtered water.
Active Chemistry

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