0 Members and 1 Guest are viewing this topic.
Hi all, I'm testing for ions but am clueless to what is/are the rationale(s) behind the steps that were carried out. Can someone enlighten me on the following questions:===============================================Tests conducted===============================================A. To test for Chloride:1) Acidify with dilute Nitric Acid2) Add Silver Nitrate solution.B. To test for Sulphate:1) Acidify with dilute Hydrochloric Acid2) Add a few drops of Barium Chloride solution.C. To test for Nitrate:1) Acidfy with dilute Sulphuric Acid2) Add a few crystals of Ferrous Sulphate3) Shake to dissolve4) Add concentrated Sulphuric Acid slowly, allowing it to settle at bottom of test tube.===============================================Q1: Why are different acids being used for the 3 tests?Q2: How do we know if the solution is completely acidified?Q3: In Test C, brown ring is observed if Nitrate ions are present. What is the brown ring due to?Q4: Is it possible to write chemical equation for the above questions? If yes, how do i write them?Q5: In the preliminary test, I added excess Sodium Carbonate to an unknown sample. I then added distilled water, placed it over a bunsen flame, heated it to slow boiling with intermitten stirring for 5 minutes. Why do I have to add excess Sodium Carbonate in this preliminary step?