Dilute sulfuric acid reacts with a colourless solution to form a white precipitate. May I know what the colourless solution is?
I wrote calcium hydroxide. Are there any other answers?
and by the way, to test for (SO4)2- ions, you add dilute nitric/hydrochloric acid before adding barium nitrate/chloride. But there is no reaction between sulfuric acid and barium sulphate, is there?
Originally posted by bonkysleuth:Dilute sulfuric acid reacts with a colourless solution to form a white precipitate. May I know what the colourless solution is?
I wrote calcium hydroxide. Are there any other answers?
and by the way, to test for (SO4)2- ions, you add dilute nitric/hydrochloric acid before adding barium nitrate/chloride. But there is no reaction between sulfuric acid and barium sulphate, is there?
The reason you add protons (ie. H+ ions), is to remove any carbonate ions present, and/or hydroxide ions present, that might give false positives (ie. another ppt which may mislead you into thinking the test result is positive).
Go to my thread "Collection of Questions" here (http://www.sgforums.com/forums/2297/topics/320107), and then find (control-F) "acidify silver nitrate".
As for the colourless solution, one possible answer (and the one most likely required at 'O' levels) is barium nitrate solution.
Ba2+(aq) + SO4 2-(aq) --> BaSO4(s)
Originally posted by UltimaOnline:
The reason you add protons (ie. H+ ions), is to remove any carbonate ions present, and/or hydroxide ions present, that might give false positives (ie. another ppt which may mislead you into thinking the test result is positive).
Go to my thread "Collection of Questions" here (http://www.sgforums.com/forums/2297/topics/320107), and then find (control-F) "acidify silver nitrate".
As for the colourless solution, one possible answer (and the one most likely required at 'O' levels) is barium nitrate solution.
Ba2+(aq) + SO4 2-(aq) --> BaSO4(s)
Ok, thanks.
Is it okay to write barium chloride? You'd still get BaSO4.
Originally posted by bonkysleuth:Ok, thanks.
Is it okay to write barium chloride? You'd still get BaSO4.
Yes, it's fine.