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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
Name a solution that will separate the component of the following mixture: CaO from PbO
You are given a mixture of precipitated copper hydroxide and zinc hydroxide. Name a solvent which will dissolve:
Both copper hydroxide and zinc hydroxide
The questions (i) to (v) refer to the following salt solutions listed A to F :
A. Copper nitrate
B. Iron (II) sulphate
C. Iron (III) chloride
D. Lead nitrate
E. Magnesium sulphate
F. Zinc chloride
(i) Which two solutions will give a white precipitate when treated with dilute hydrochloric acid followed by barium chloride solution/
(ii) Which two solutions will give a white precipitate when treated with dilute nitric acid followed by silver nitrate solution?
(iii) Which solution will give a white precipitate when either dilute hydrochloric acid or dilute sulphuric acid is added to it?
(iv) Which solution becomes a deep/inky blue colour when excess of ammonium hydroxide is added to it?
(v) Which solution gives a white precipitate with excess ammonium hydroxide?
State the colour of the residue formed when nitrates of :
1. Calcium
2. Zinc
3. Lead
4. Copper are strongly heat
Write a balanced equation for the following conversion:
\[\ce{ZnSO4 ->[A]Zn(OH)2->[B]Na2ZnO2}\]
Sodium hydroxide solution is added to solution A. A white precipitate is formed which is insoluble in excess sodium hydroxide solution. What is the metal ion present in solution A?
Write balanced equation for a coloured metallic oxide which dissolves in alkalis to yield colourless solutions.
An amphoteric oxide.
Write balanced equation for a metal that evolves a gas which burns with a pop sound when boiled with alkali solutions.
Write balanced equation for a coloured metallic oxide which dissolves in alkalis to yield colourless solutions.
