(i) Pale blue precipitate of Cu(OH)2 is formed, which becomes deep blue when excess of ammonium hydroxide is added.
CuSO4 + 2NH4OH ⟶ (NH4)2SO4 + Cu(OH)2 ↓
Cu(OH)2 + (NH4)2SO4 + 2NH4OH [in excess] ⟶ 4H2O + [Cu(NH3)4]SO4
(ii) Gelatinous white precipitate of zinc hydroxide is formed which becomes colourless solution on adding excess of ammonium hydroxide.
ZnSO4 + 2NH4OH ⟶ (NH4)2SO4 + Zn(OH)2 ↓
Zn(OH)2 +(NH4)2SO4 + 2NH4OH [in excess] ⟶ 4H2O + [Zn(NH3)4]SO4
| Zinc oxide | ZnO + NaOH ⟶ ____ + ____ |
| Zinc hydroxide | Zn(OH)2 + NaOH ⟶ ____ + ____ |
| Lead [II] oxide | PbO + NaOH ⟶ ____ + ____ |
| Lead hydroxide | Pb(OH)2 + NaOH ⟶ ____ + ____ |
| Aluminium oxide | Al2O3 + NaOH ⟶ ____ + ____ |
| Aluminium hydroxide | Al(OH)3 + KOH ⟶ ____ + ____ |
| Zinc | Zn + NaOH ⟶ ____ + ____ |
| Zinc | Zn + KOH ⟶ ____ + ____ |
| Lead | Pb + NaOH ⟶ ____ + ____ |
| Lead | Pb + KOH ⟶ ____ + ____ |
| Aluminium | Al + NaOH + H2O ⟶ ____ + ____ |
| Aluminium | Al + KOH + H2O ⟶ ____ + ____ |
| Magnesium chloride | MgCl2 + NH4OH ⟶ ____ + ____ ↓ |
| Iron [II] sulphate | FeSO4 + NH4OH ⟶ ____ + ____ ↓ |
| Iron [III] chloride | FeCl3 + NH4OH ⟶ ____ + ____ ↓ |
| Copper [II] sulphate | CuSO4 + NH4OH ⟶ ____ + ____ ↓ [Cu(OH)2 + (NH4)2SO4 + NH4OH [in excess] ⟶ ____ + ____] |
| Zinc sulphate | ZnSO4 + NH4OH ⟶ ____ + ____ ↓ [Zn(OH)2 +(NH4)2SO4 + NH4OH [in excess] ⟶ ____ + ____] |
| Lead nitrate | Pb(NO3)2 + NH4OH ⟶ ____ + ____↓ |