Ammonium hydroxide is added first in a small quantity and then in excess to a solution of copper sulphate. Which of the following observation can be made?

Pale blue / bluish white precipitate is formed which is soluble in excess of

N H_{4} O H

and deep blue / inky blue solution is formed

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Pale blue / bluish white precipitate is formed which is soluble in excess of

N H_{4} O H

and deep black solution is formed

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Pale red / redish white precipitate is formed which is soluble in excess of

N H_{4} O H

and deep blue / inky blue solution is formed

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Pale red / redish white precipitate is formed which is soluble in excess of

N H_{4} O H

and deep red / inky red solution is formed

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Solution

The correct option is B Pale blue / bluish white precipitate is formed which is soluble in excess of $N H_{4} O H$ and deep blue / inky blue solution is formed
When $N H_{4} O H$ solution is added drop by drop to copper sulphate solution a pale blue / bluish white precipitate is formed which is soluble in excess of $N H_{4} O H$ and deep blue / inky blue solution is formed.

$C u S O_{4} + 2 N H_{4} O H \to C u (O H)_{2} + (N H_{4})_{2} S O_{4}$

$C u (O H)_{2} + 4 N H_{4} O H \to C u (N H_{3})_{4} (O H)_{2} + 4 H_{2} O$

Therefore, option A is correct.

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Similar questions

When ammonium hydroxide is added to solution B, a pale blue precipitate is formed . This pale blue precipitate dissolves in excess of ammonium hydroxide giving an inky blue solution. Name the cation present in solution B.

Q. (a) Sodium hydroxide solution is added to solution A. A white precipitate is formed which is insoluble in excess sodium hydroxide solution. Name the metal ion present in solution A.
(b) When ammonium hydroxide is added to solution B, a pale blue precipitate is formed. This pale blue precipitate dissolves in excess ammonium hydroxide to give an inky blue solution. Name the cation present in solution B. What is the probable colour of solution B?

Q. The following table shows the test a student performed on four different aqueous solution which are X, Y, Z and W. Based on the observations provided, identify the action present.

Chemical test	Observation	Conclusion
To solution X, ammonium hydroxide is added in minimum quantity first and then in excess.	A dirty white precipitate is formed which dissolves in excess to form a clear solution.
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.
To solution W a small quantity of sodium hydroxide solution hydroxide solution is added and then in excess.	A white precipitate is formed which remains insoluble.
To a salt Z calcium hydroxide solution is added and then heated.	A pungent smelling gas turning moist red litmus paper blue is obtained.

Q. When ammonium hydroxide is added to solution B, a pale blue precipitate is formed. This pale blue precipitate dissolves in excess ammonium hydroxide to give an inky blue solution. What is the cation [positive ion] present in solution B? What is the probable colour of solution B?

Q. When ammonium hydroxide 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 [positive ion] present in solution B? What is the probable colur of solution B.

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