Transition Metals Cobalt

Question 1

[Co(H2O)6]2+
Metal ion-
Ligand-
Colour-

Answer 1

Metal ion- Cobalt (II)
Ligand- Water
Colour- Pink

Question 2

[Co(NH3)6]2+
Metal ion-
Ligand-
Colour-

Answer 2

Metal ion- Cobalt (II)
Ligand- Ammonia
Colour- Straw-coloured (oxidised to Co3+ by air, so darkens on standing)

Question 3

[Co(NH3)6]3+
Metal ion-
Ligand-
Colour-

Answer 3

Metal ion- Cobalt (III)
Ligand- Ammonia
Colour- Yellow
(may appear dark brown)

Question 4

[CoCl4]2-
Metal ion-
Ligand-
Colour-

Answer 4

Metal ion- Cobalt (II)
Ligand- Chloride ions
Colour- Blue

Question 5

[Co(H2O)4(OH)2]
Metal ion-
Ligand-
Colour-

Answer 5

Metal ion- Cobalt (II)
Ligand- Water and hydroxide ions
Colour- Green-blue ppt.

Question 6

CoCO3
Metal ion-
Ligand-
Colour-

Answer 6

Metal ion- Cobalt (II)
Ligand- N/A
Colour- Pink ppt.