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Question
What happens when ammonia solution is added first dropwise and then in excess to the following solution:
CuSO4
Write a balanced equation for this reaction.
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Solution
\[\ce{\underset{\text{blue}}{CuSO4} + 2NH4OH -> \underset{\text{pale blue ppt.}}{Cu(OH)2\downarrow} + \underset{\text{colourless in solution}}{(NH4)2SO4}}\]
With excess of NH4OH , ppt. dissolves
\[\ce{Cu(OH)2 + 4NH4OH -> \underset{(Deep Blue Solution)}{\underset{Tetrammine copper (II) hydroxide}{[Cu(NH3)4](OH2)}} + 4H2O}\]
RELATED QUESTIONS
Name the metal hydroxides which are soluble in ammonium hydroxide solution.
Distinguish between the given pair of compounds using the test given within brackets:
A lead salt and a zinc salt (using excess ammonium hydroxide)
State two relevant observations of the following:
Ammonium hydroxide solution is added to zinc nitrate solution in minimum quantities and then in excess.
State what do you observe when ammonium hydroxide to Iron (III) sulphate solution.
Write the observation for the following :
NH4OH is added first in a small quantity and then in excess to a solution of copper sulphate.
What would you observe in the following cases:
Ammonium hydroxide is first added in a small quantity and then in excess to a solution of copper sulphate.
The following table shows the tests a student performed on four different aqueous solutions which are X,Y,Z and W. Based on the observations provided, Identify the cation present
|
Chemical Test |
Observation | Conclusion |
| To Solution X, ammonium hydroxide is added in minium quantity first and then in excess | A dirty white precipitate is formed which dissolves in excess to form a clear solution | (i) |
| To Solution Y, ammonium hydroxide is added in minimum quantity first and then in excess | A pale blue precipitate is formed which dissolves in excess to form a clear inky blue solution | (ii) |
| To solution W, A small quantity of sodium hydroxide solution is added and then in excess | A white precipitate is formed which remains insoluble | (iii) |
| To a salt Z, calcium hydroxide solution is added and then heated | A pungent smelling gas turning moist red litmus paper blue is obtained | (iv) |
Identify the cation of the following case:
NH4OH solution when added to solution (B) gives white ppt. which does not dissolve in excess.
______ is a white precipitate that is soluble in excess of Ammonium hydroxide solution.
The metal hydroxide which reacts with both acids and alkalis to form salt and water is ______.
