Acidified silver nitrate

Discussion in 'Supporting Chemistry' started by DMS, Feb 14, 2020.

  1. DMS

    DMS

    Hello all, does anyone have a recipe for acidified silver nitrate please? TIA
     
  2. You acidify solutions with nitric acid before you test them with the silver nitrate, but I have never heard of acidifying the silver nitrate.
    Why do they want acidified silver nitrate? Curious because I have never been asked for it so interested to know.
     
  3. DMS

    DMS

    Yes, that's what we thought too. It is a request from a teacher to test for chloride ions, but on looking through our stocks we seem to have made it before - we think, for an exam. We've looked for recipe on Cleapss but there isn't one, that's why I asked if anyone else had done it this way.
     
  4. I've got some on the shelf in my prep-lab lablled as 0.1M acidified Silver Nitrate - I think it was for the old edexcel GCSE chemistry - I'll try and find the recipe
     
  5. Yes it is used in the test for a chloride. The acid is added so that any Carbonate present is broken down and no false positives are given.
     
  6. My recipe stated a few drops of nitric acid added to 0.1M Silver nitrate.


    The solution is acidified by adding dilute nitric acid. (Remember: silver nitrate + dilute nitric acid.) The nitric acid reacts with, and removes, other ions that might also give a confusing precipitate with silver nitrate.

    Silver nitrate solution is then added to give:

    ion present observation
    F-
    no precipitate
    Cl- white precipitate
    Br- very pale cream precipitate
    I- very pale yellow precipitate
     
  7. I've already said that Peter - no white silver carbonate is formed .
     
  8. you didn't say the recipe (concentration or the amount of nitric acid) which what @DMS asked for,.I have.
     
  9. My recipe stated a few drops of nitric acid added to 0.1M Silver nitrate.
     
  10. All it needs to be is acidified. The amount added does not have to be prescise.
     
  11. nearly a recipe and certainly not precise.
     
  12. DMS

    DMS

    Thankyou Peter and George. Normally we just give out the nitric acid and silver nitrate separately, however, we must have given out the acidified soln at some point in the past but had no record of the recipe.
     
  13. I never thought about acidifying the silver nitrate beforehand... it's a good idea but most procedures (at least Edexcel) specifically ask for students to add nitric acid which could be an examined step in an exam question if asked how to carry out a halide test.