Ligand Substitution Reactions

Question 1

What is the colour of [Cu(H2O)6]2+ in solution?

Answer 1

Pale Blue

Question 2

State the reaction between [Cu(H2O)6]2+ and 4Cl-

State the colour (in solution) of the complex ion formed.

Answer 2

[Cu(H2O)6]2+ + 4Cl- ⇌ [CuCl4]2- + 4H2O

Yellow

Question 3

State the reaction between [Cu(H2O)6]2+ and 4NH3.

State the colour (in solution) of the complex ion formed.

Answer 3

[Cu(H2O)6]2+ 4NH3 ⇌ [Cu(H2O)2(NH3)4]2+ + 4H2O

Dark Blue

Question 4

What is the colour of [Cr(H2O)6]3+ in solution?

Answer 4

Violet (in practice, it is green)

Question 5

State the reaction between [Cr(H2O)6]3+ and 6NH3.

State the colour (in solution) of the complex ion formed.

Answer 5

[Cr(H2O)6]3+ + 6NH3 ⇌ [Cr(NH3)6]3+ + 6H2O

Purple