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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?
- What is the formula of the white gelatinous precipitate obtained?
On addition of dilute ammonia solution to a colourless salt solution, a white gelatinous precipitate is formed which dissolves when ammonia solution is in excess. Identify the metal from Na, Al, Pb, Fe, Zn whose salt solution is used. What is the formula of the precipitate formed?
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उत्तर
(a) Zinc (Zn) metal salt solution was used.
(b) The formula of the white gelatinous precipitate is Zn(OH)2.
Concept Insight:
\[\ce{\underset{Colourless}{ZnSO4} + 2NH4OH ->\underset{White ppt.}{Zn(OH)2} + (NH4)2SO4}\]
With an excess of NH4OH the precipitate of zinc(II) hydroxide dissolves as:
\[\ce{Zn(OH)2 +\underset{In excess}{(NH4)2SO4 + 2NH4OH} ->\underset{\underset{(Colourless solution)}{Tetrammine zinc(II)Sulphate}}{[Zn(NH3)4]SO4}+ 4H2O}\]
संबंधित प्रश्न
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Name the probable cation present in each of the following solution:
Light blue coloured solution
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Write the colour of the following salt : Ferric salts.
Write the colour of the following salt : Calcium salts.
A metal whose alloy finds use in the construction of aircrafts in the powdered form is added to sodium hydroxide solution. A colourless gas was evolved and after reaction was over, the solution was colourless.
(a) Name the powdered metal added to sodium hydroxide solution.
(b) Name the gas evolved.
(c) Name the salt present in the colorless solution.
State what do you observe when:
Lead nitrate and sodium chloride are mixed.
Write the observation, and balanced equation for the following reaction:
Moist starch iodide paper is placed at the mouth of a test tube containing chlorine gas.
Name the probable cation present based on the following observation:
White precipitate insoluble in NH4OH but soluble in NaOH.
