Copper forms complexes with chloride ions and with ammonia.

log₁₀ K_stab for aqueous Cu²⁺ ions with Cl– as a ligand is 2.80.

log₁₀ K_stab for aqueous Cu²⁺ ions with NH₃ as a ligand is 4.25.

a. A few drops of hydrochloric acid are added to blue aqueous copper(II) sulfate.

i. Copy and complete the equation for this reaction.

ii. Describe and explain what happens when excess water is then added to the reaction mixture in part i.

iii. Explain what happens in terms of ligand exchange, when concentrated aqueous ammonia is added to the reaction mixture from part ii.

b. Aqueous copper ions form a complex with 1,2-diaminoethane, NH₂CH₂CH₂CH₂NH₂. They also form a complex with 1,3-diaminopropane NH₂CH₂CH₂CH₂NH₂.

log₁₀ K_stab for aqueous Cu²⁺ ions with 1,2-diaminoethane as a ligand is 20.3

log₁₀ K_stab for aqueous Cu²⁺ ions with 1,3-diaminopropane as a ligand is 17.7

i. What type of ligands are 1,2-diaminoethane and 1,3-diaminopropane? Explain your answer.

ii. Which one of these ligands forms a more stable complex? Explain your answer.

iii. 1,2-diaminoethane can be abbreviated as ‘en’.

A complex of nickel ions, Ni²⁺, with 1,2-diaminoethane is octahedral in shape with a co-ordination number of 6. Draw the structures of the two stereoisomers of this complex.

Transcribed Image Text:

[Cu(H,O)?"(aq) ight blue [CuclP (aq) + yellow-green