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प्रश्न
You are given three white powders-calcium carbonate, lead carbonate and zinc carbonate. Describe the tests you would carry out in solution, to identify the metal ion in each of the above compounds. Indicate clearly how you would prepare the solutions for the tests.
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उत्तर
The solutions for the tests will be prepared by dissolving the given powders separately in water.
(i) Solution of Calcium carbonate:
Calcium carbonate is CaCO3 and contains Ca2+ ions. Sodium hydroxide solution NaOH can be used to identify Ca2+ since its addition to calcium carbonate solution will give white precipitates of Ca(OH)2 which are sparingly soluble in excess of NaOH.
(ii) Solution of Lead carbonate:
Lead carbonate is PbCO3 and contains Pb2+ ions. Ammonium hydroxide solution NH4OH can be used to identify Pb2+ since its addition to lead carbonate solution will give white precipitates of Pb(OH)2 which are insoluble in excess of NH4OH.
(iii) Solution of Zinc carbonate:
Zinc carbonate is ZnCO3 and contains Zn2+ ions. Sodium hydroxide solution NaOH can be used to identify Zn2+ since its addition to zinc carbonate solution will give white gelatinous precipitates of Zn(OH)2 which are soluble in excess of NaOH.
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संबंधित प्रश्न
State your observations when barium chloride solution is mixed with sodium sulphate solution.
State your observation when excess sodium hydroxide is added to calcium nitrate solution
Sodium hydroxide solution is added first in a small quantity, then in excess to the aqueous salt solutions of copper (II) sulphate, zinc nitrate, lead nitrate, calcium chloride and iron (III) sulphate. Copy the following table and write the colour of the precipitate in (i) to (v) and the nature of the precipiatate (soluble or insoluble) in (vi) to (x)
| Aqueous salt Solution | Colour of Participitate when NaOH is added in a samll quantity | Nature of precipitate(soluble or insoluble) when NaOH added in excess |
| Copper (II) Solution | ||
| Zinc nitrate | ||
| Lead nitrate | ||
| Calcium chloride | ||
| Iron(III) sulphate |
Give one chemical test to distinguish between the following pair of compounds:
Iron (II) chloride solution and iron (III) chloride solution
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Name the products formed when the reaction with two different amphoteric oxides with a caustic alkali.
Write a balanced equation for the following conversion:
\[\ce{ZnSO4 ->[A]Zn(OH)2->[B]Na2ZnO2}\]
When an ammonium hydroxide solution is added to solution B, a pale blue precipitate is formed. This pale blue precipitate dissolves in excess ammonium hydroxide giving an inky blue solution. What is the cation present in solution B?
Write a balanced equation for a coloured metallic oxide which dissolves in alkalis to yield colourless solutions.
Write balanced equations for a coloured metallic oxide which dissolves in alkalis to yield colourless solutions.
