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प्रश्न
You are provided with PbCO3, ZnCO3 and CaCO3. How will you identify these cations?
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उत्तर
By use of Ammonium hydroxide we can identify the ions PbCO3, ZnCO3 and CaCO3 as :
(i) \[\ce{PbCO3 + 2NH4OH -> Pb(OH)2 v + 2NH4NO3}\]
Pb(OH)2 forms white precipitate which are insoluble in excess ammonium hydroxide.
(ii) \[\ce{ZnCO3 + NH4OH -> Zn(OH)2 v + 2Na2CO3}\]
Zn(OH)2 forms white gelatinous precipitate which are soluble in excess ammonium hydroxide.
(iii) \[\ce{CaCO3 + NH4OH -> Ca(OH)2 + 2Na2CO3}\]
No precipitation of Ca(OH)2 occurs even with addition of excess of NH4OH. Because the concentration of hydroxide ion from ammonium hydroxide is so low that it cannot precipitate the hydroxide of calcium.
Concept Insight : Some precipitated metallic hydroxides by ammonium hydroxide become soluble hydroxides when treated with excess of ammonium hydroxide due to the formation of a soluble complex salt in the presence of excess of ammonium hydroxide.
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संबंधित प्रश्न
On adding dilute ammonia solution to a colourless solution of a salt, a white gelatinous precipitate appears. This precipitate however dissolves on addition of excess of ammonia solution. Identify (choose from Na, Al, Zn, Pb, Fe)
Which metal salt solution was used?
On adding dilute ammonia solution to a colourless solution of a salt, a white gelatinous precipitate appears. This precipitate however dissolves on addition of excess of ammonia solution. Identify (choose from Na, Al, Zn, Pb, Fe)
What is the formula of the white gelatinous precipitate obtained?
Write the observation, and balanced equation for the following reaction:
Ammonium hydroxide is added first in a small quantity, and then in excess, to a solution of copper sulphate.
State two relevant observation of the following:
Ammonium hydroxide solution is added to copper (II) nitrate solution in small quantities and then in excess
State two relevant observations of the following:
Ammonium hydroxide solution is added to zinc nitrate solution in minimum quantities and then in excess.
Write balanced equation copper sulphate solution with ammonium hydroxide solution.
The salt solution which does not react with ammonium hydroxide is ______.
______ is a white precipitate that is soluble in excess of Ammonium hydroxide solution.
Identify the cation in the following case:
Ammonium hydroxide solution when added to Solution B gives a white precipitate which does not dissolve in excess of ammonium hydroxide solution.
Write balanced equation:
Copper sulphate solution with ammonium hydroxide solution.
