Ammonium solution +CUSO4 very easy

Chemical equation:
2NH4OH (aq) + CuSO4 (aq) → Cu(OH)2 (s) + (NH4)2SO4 (aq)

Ionic equation:
2OH- (aq) + Cu2+ (aq) → Cu(OH)2 (s)


Observations:
1. Pale blue precipitate is formed. [Cu(OH)2(s), copper (II) hydroxide]
2. The colour of the blue solution fades. (Because the concentration of copper (II) ions decrease.)
3. Heat is evolved. (This is a precipitation reaction, it is exothermic.)

除o左出 blue ppt，blue colour of the solution becomes paler.

2NH4OH(aq)+CuSO4(aq)------》(NH4)2SO4(aq)+Cu(OH)2(s)

會有blue ppt出黎......