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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: chemistrie on December 23, 2004, 11:21:25 PM

Title: Complex salts
Post by: chemistrie on December 23, 2004, 11:21:25 PM
In my chemistry lesson, I know that zinc and copper will redissolve in excess ammonia  and becomes colorlesss solutions, what are the ions responsible for that?
Title: Re:Complex salts
Post by: HongKongALevelboy on December 24, 2004, 04:44:38 AM
for Zn , it should be [Zn(NH3)4]+ which is colorless .
for Cu , i have doubt because Cu(ii) complex should have blue color which is [Cu(NH3)4]2+ , can anybody answer me ?
Title: Re:Complex salts
Post by: kevins on December 24, 2004, 07:15:32 AM
Yes, [Zn(NH3)4]+  is colorless and [Cu(NH3)4]2+  is deep blue in colour.
Title: Re:Complex salts
Post by: Donaldson Tan on December 24, 2004, 07:34:13 AM
In my chemistry lesson, I know that zinc and copper will redissolve in excess ammonia  and becomes colorlesss solutions, what are the ions responsible for that?

chemistrie: I'm sure you meant Zinc(II) Hydroxide and Copper(II) Hydroxide redissolve in excess ammonia. cheers~
Title: Re:Complex salts
Post by: NISHANT on December 30, 2004, 10:18:58 PM
this should be simple:
zinc has its orbital octet complete so its electrons cannot travel to higher energy level and hence do not absorb light.As we move along a period valency of electrons first increases then decreases so you can say that the intensity of light absorbed first increases then decreases.by this defination copper salts emit blue light. the reagent you've given is called SHWITZZER'S REAGENT.
Title: Re:Complex salts
Post by: Donaldson Tan on December 30, 2004, 11:11:06 PM
for Zn , it should be [Zn(NH3)4]+ which is colorless .
for Cu , i have doubt because Cu(ii) complex should have blue color which is [Cu(NH3)4]2+ , can anybody answer me ?

shouldnt it be [Zn(NH3)4]2+ ???