When ammonia is added to green aqueous solution of nickel (II) sulphate, the colour of the solution changes to the violet. This is caused by

Monjur Alahi

When ammonia is added to green aqueous solution of nickel (II) sulphate, the colour of the solution changes to the violet. This is caused by
A. nickel ion undergoing a change in oxidation state
B. ammonia molecules replacing water molecules surrounding nickel
C. change in co-ordination number of nickel
D. change in pH value of the solution.


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Salim Ahmed Kawsar

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Correct Answer - B
The colour change is due to replacement of water molecules surrounding Ni by the ammonia molecules.

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