Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Blue lake test .HELP

  1. Oct 26, 2005 #1
    blue lake test.....HELP

    aluminium ions presence in a salt is confirmed by performing a test called blue lake test i have been trying to get it rught in my chem lab for weeks but in vain can anyone suggest the exact method i should use the way i perform the test is that i take solution of aluminium salt in a test tube add few drops of litmus solution then acidify with dil. HCl then add NH4OH(ammonium hydroxide) and allow to stand . the result i should get is blue ppt. floating in colourless solution but i haven't got this result at all can anyone help me perform the test better?
     
  2. jcsd
  3. Oct 26, 2005 #2

    chem_tr

    User Avatar
    Science Advisor
    Gold Member

    Maybe you need to review what's been happening in the experiment. You add litmus, whose color is blue in alkaline solutions. It is possible that the concentration of HCl is too low to provide required acidity, but ammonia solution is more concentrated than HCl to yield a basic solution eventually. I do not think that the precipitate is actually blue, it is colored by litmus; I recall that [Al(NH3)6]3+ is colorless, and I think you got this compound in your experiment.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Blue lake test .HELP
  1. Is water blue? (Replies: 16)

Loading...