Exercise 1 Question 5
How does ammonia react with a solution of Cu2+?
Ammonia acts as a Lewis base due to the presence of lone pair of electrons on the nitrogen atom.Therefore,it can form coordinate bond with electron deficient molecules or a number of transition metal cations to from complex compounds.Ammonia reacts with a solution of Cu2+ to from a deep blue coloured complex.The reaction for the above complex can be written as follows:
Cu2+(aq) + 4 NH3(aq) ⇔ [Cu(NH3)4]2+(aq)
Blue Deep Blue
This property of ammonia to form complex compounds is useful in detection of metal ions.
