1. Add 1ml of 0.1M copper 2 sulfate solution into a test tube. Add drops of 2M ammonia solution until a light blue precipitate of cuoh2 forms.
2. Add more drops of ammonia until a solution cantaining the complex ion Cu(NH3)4] 2+ forms.
Write an equation for this reaction
Cu2+ + 4NH3 → [Cu(NH3)4]2+
The equation for the formation of the light blue precipitate of Cu(OH)2 can be represented as follows:
CuSO4(aq) + 2NH4OH(aq) → Cu(OH)2(s) + (NH4)2SO4(aq)
Next, for the formation of the complex ion Cu(NH3)4]^2+, the equation is:
Cu(OH)2(s) + 4NH3(aq) → [Cu(NH3)4]^2+(aq) + 2OH^-(aq)
To write the equation for the reaction described, we need to understand the chemical reactions occurring when copper(II) sulfate reacts with ammonia. Here are the step-by-step reactions:
1. Copper(II) sulfate reacts with ammonia to form a light blue precipitate of copper(II) hydroxide:
CuSO4(aq) + 2NH3(aq) → Cu(OH)2(s) + (NH4)2SO4(aq)
2. Excess ammonia reacts with the copper(II) hydroxide to form the complex ion copper(II) tetraammine:
Cu(OH)2(s) + 4NH3(aq) → [Cu(NH3)4]2+(aq) + 2OH-(aq)
Therefore, the overall equation for the reaction is:
CuSO4(aq) + 6NH3(aq) → [Cu(NH3)4]2+(aq) + (NH4)2SO4(aq) + 2OH-(aq)