Copper Complexes

Hazards

• Concentrated HCl is corrosive and toxic.
• Concentrated Ammonum hydroxide is corrosive and toxic.

Chemicals and Solutions

• 0.1M Copper sulfate, CuSO₄
• Concentrated Hydrochloric acid, HCl
• Conc. Ammonium hydroxide, NH₄OH

Materials

3 tall hydrometer cylinders

Procedure

1. Place 150 mL into each of 3 cylinders.
2. To the first cylinder and 100 mL conc. HCl. The solution turns green forming CuCl₄₂-.
3. To the first cylinder and 100 mL conc. HCl. The solution turns green forming CuCl₄₂-.
4. To the second cylinder add a few drops conc. NH₄OH and stir. A light blue ppt. of Cu(OH)₂ will form.
5. To the third cylinder add 50 mL conc. NH₄OH and stir to get super-blue color of Cu(NH₃)₄₂+