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Topic: other barium and strontium tests  (Read 5167 times)

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student16

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other barium and strontium tests
« on: December 21, 2005, 02:57:29 AM »
For school, we are testing an Unknown, and for Barium and Strontium
I've already tried flame tests, but could never get the supposed colors for the unknown or solutions of the ions.  Are there any other test to see if there are Barium or Strontium ionss?

Offline Albert

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Re:other barium and strontium tests
« Reply #1 on: December 21, 2005, 07:03:11 AM »
Flame tests are still the best for discriminating between Barium and Strontium.

However, you can try this (I never did it: just read on a book): add dilute H2SO4 or copper sulfate.
Try to dissolve the precipitate with hydrochloric acid: SrSO4 is soluble, while BaSO4 isn't.
« Last Edit: December 21, 2005, 07:06:58 AM by Albert »

Offline Alberto_Kravina

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Re:other barium and strontium tests
« Reply #2 on: December 21, 2005, 03:39:20 PM »
Try flame tests (as Albert said) Barium has a green color and strontium a brick-red flame.
The best way to distinguish the two cations, however, is trying to precipitate the Ba2+ with potassium chromate in acetic acid acid-sodium acetate buffer. Yellow precipitate shows Ba2+.
If Barium is present filter the chromate, neutralize with Na2CO3 and test for strontium with sulfate. White precipitate of SrSO4 shows Sr

PS: Use a spectrometer to distinguish the colors.
« Last Edit: December 21, 2005, 03:40:20 PM by Alberto_Kravina »

student16

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Re:other barium and strontium tests
« Reply #3 on: December 21, 2005, 04:59:24 PM »
alright thanks I try those

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