(Cr2O72- does not form a precipitate with Ba2+)!
2CrO4^2-(aq) + 2H+(aq) Cr2O7^2-(aq) + H2O(l)
2007-04-17 14:25:29 · 3 answers · asked by shevchenko 1 in Science & Mathematics ➔ Chemistry
oops sorry, it's
2CrO4^2-(aq) + 2H+(aq) <==> Cr2O7^2-(aq) + H2O(l)
2007-04-17 14:33:45 · update #1
we have added HCL and NaOH to it before adding Ba(NO3)2(aq)
2007-04-17 14:37:03 · update #2
This is not a redox reaction; per se. It s only when you start to deal with acid or base extremes that it becomes one.
The acidified dichromate is a powerful oxidizing agent; but it cannot oxidise barium nitrate
Barium chloride is very soluble
Barium nitrate is soluble; but to around one quarter that of the chloride
Barium chromate is sparingly soluble (virtually insoluble) but has different solubilty when the pH is away from that of water (7)
Barium dichromate is soluble; but the value was quite hard to find.
Potassium dichromate + barium nitrate -> barium dichromate + potassium nitrate.
All 4 are soluble so there should be no double decomposition reaction. The cloudiness will probably be due to the swirling of the two different coloured solutions that will quickly disappear as the orange potassium dichromate solution and the colourless barium nitrate solution mix.
Efffect of HCl (in the dichromate) when added:
Still not a redox reaction, and both potassium and barium chlorides are quite soluble, so NO double decomposition reaction occurs either.
BUT, if there is a small amount of chromate present, the acid will react to push it across to the dichromate - which is soluble. It may be the reason that you see passing cloudiness, the dichromate solution was "going off".
Efffect of NaOH (in the dichromate) when added:
"Because the reaction of the OH- ions will remove some of the H+, this will cause a large amount of CrO42- ions to form in the solution. Much more precipitate will form since there are now enough CrO42- ions for the Ba2+ to react with." - straight copy from the second website reference.
2007-04-23 01:38:35 · answer #1 · answered by big_george 5 · 0⤊ 0⤋
If the acid was supplied as HCl, some BaCl2 ppt may form.
2007-04-17 21:29:22 · answer #2 · answered by cattbarf 7 · 1⤊ 1⤋
whats does that mean, dude!!!
2007-04-17 21:28:25 · answer #3 · answered by pink567 1 · 0⤊ 2⤋