Question

Question : When small amount of ammonia is added to CUSO4 solution in water, blue PPt of [Cu(H2O)4(OH)2] is formed. The blue PPt dissolves on addition of excess of ammonia.The product formed is:
[Cu(H2O)2 (NH3)2 (OH)2]
[Cu(NH3)4 (OH)2]
[Cu (NH3)4 (H2O)2]2+
[Cu (NH3)3 (H2O3]2+
​

Answer 1

Answer:

When NH

4

OH solution is added drop by drop to copper sulphate solution a pale blue / bluish white precipitate is formed which is soluble in excess of NH

4

OH and deep blue / inky blue solution is formed.

CuSO

4

+2NH

4

OH→Cu(OH)

2

+(NH

4

)

2

SO

4

Cu(OH)

2

+4NH

4

OH→Cu(NH

3

)

4

(OH)

2

+4H

2

O