Colour of complex ions!! HELP!!!! (Edexcel syllabus)

OK so mayb its not good to find out the day before th exam that ive lost my notes on this!!! (and mayb the unit book too!!)

so does anyone have the colours of the complex ions like Cr(h2o)2+ and then when u add ammonia to it what happens etc etc for the first line of d block elemenmts!!!!

anyone who can help me is a complete star!! thanku!!!

Reply 1

alkaeda

here is something from my notes, sorry if its not all legible, ive tried to put the colour and the complex in the same box. hope this helps a little..

DSC00304.JPG408.9KB

Reply 2

yoyo87

Examples of some equations to help you with alkaeda notes

COBALT
Add with sodium hydroxide:
[Co(H20)6]3+ + 3OH- ------> Co(OH)3 + 6H20 Green sol-->green ppt
Add excess sodium hydroxide
Co(OH)3 + 3OH- -------> [Co(OH)6]3- Green ppt-->green sol
Add with NH3:
[Co(H20)6]3+ + NH3+ --> Co(OH)3 + NH4+ + H20 Gren sol->green ppt
Add with excess NH3:
NOTHING HAPPENS

ZINC:
Add with sodium hydroxide:
[Zn(H20)6]2+ + 2OH- ------> Zn(OH)2 + 6H20 None-->white ppt
Add excess sodium hydroxide
Zn(OH)2 + 2OH- -------> [Zn(OH)4]2- White ppt-->colourless
Add with NH3:
[Zn(H20)6]2+ + NH3+ --> Zn(OH)2 + NH4+ + H20 None->White ppt
Add with excess NH3:
Zn(OH)2(H20)4 + 4NH3+ --> [Zn(NH3)4]2+ + 2OH- + 2H20 White ppt--> Colourless

This is real long lol