Colours Of Aqueous Ions

Question 1

What is the colour and state of [Cu(H2O)6]2+?
What is formed and what’s it colour and state with
NaOH
NH3
Xs NH3
Na2CO3
Cl-

Answer 1

Blue sol 
[Cu(H2O)4(OH)2] Blue ppt 
[Cu(H2O)4(OH)2] Blue ppt 
[Cu(NH3)4(H2O)2] Deep blue sol 
CuCO3 Blue ppt 
(CuCl4)2- Yellow green

Question 2

What is the colour and state of [Co(H2O)6]2+?
What is formed and the colour and state with:
NaOH
NH3
Xs NH3
Na2CO3
Cl-

Answer 2

Pink sol 
[Co(H2O)4(OH)2] Blue/green ppt 
[Co(H2O)4(OH)2] Blue/green ppt 
[Co(NH3)6]2+ Straw sol
CoCO3 Mauve ppt
(CoCl4)2- Blue

Question 3

What is the colour and state of [Fe(H2O)6]3+?
What is formed and the colour at state with:
NaOH
NH3
Na2CO3

Answer 3

Pale violet sol
[Fe(H2O)3(OH)3] Brown ppt
[Fe(H2O)3(OH)3] Brown ppt
[Fe(H2O)3(OH)3] Brown ppt

Question 4

What’s the colour and state of [Cr(H2O)6]3+?
What’s formed and the colour and state with
NaOH
Xs NaOH
NH3
Xs NH3
Na2CO3

Answer 4

Ruby red sol
[Cr(H2O)3(OH)3] Green ppt 
[Cr(OH)6] Green sol 
[Cr(H2O)3(OH)3] Green ppt
[Cr(NH3)4]3+ Purple sol 
[Cr(H2O)3(OH)3] Green ppt

Question 5

What is the colour and state of [Al(H2O)6]3+?
What is formed and the colour and state with
NaOH
Xs NaOH
NH3
Na2CO3

Answer 5

Colourless sol 
[Al(H2O)3(OH)3] White ppt 
[Al(OH)4]- Colourless sol 
[Al(H2O)3(OH)3] White ppt 
[Al(H2O)3(OH)3] White ppt

Question 6

What colour is and state is [Fe(H2O)6]2+?
What does it form and what is the colour of the product formed and state with:
NaOH
NH3
Na2CO3

Answer 6

Green sol
[Fe(H2O)4(OH)2] green ppt
[Fe(H2O)4(OH)2] green ppt
FeCO3 green ppt