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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: AdiDex on January 07, 2017, 09:35:40 AM

Title: Reaction of Copper Sulfate and ammonia .
Post by: AdiDex on January 07, 2017, 09:35:40 AM
We've done preparation of Tetraamminecopper(II) sulphate [Cu(NH3)4(H2O)n]SO4 using copper sulphate and 50% ammonia solution. Initially, a pale blue colour of Cu(OH)2 appeared with turbidity then after a dark blue colour solution is obtained. It is a substitution reaction.

Initially, why formation of Cu(OH)2 is taking place ??

Is NH3  acting as base and ripping off the proton from the complex [Cu(H2O)6]2+ ? Then on the further increment of the concentration of NH3, it starts to act as Nucleophile?? My high school teacher taught me that acid-base reactions are always fast, so in this example is everything is about kinetics? What is the role of the thermodynamics? From where can I get a quantitative explanation with proper data?
Title: Re: Reaction of Copper Sulfate and ammonia .
Post by: Borek on January 07, 2017, 12:41:33 PM
Google for copper hydroxide solubility product and amine copper complexes stability constants.

It is all about thermodynamics, no kinetics required to explain these observations.