Chlorides:
Preparation:
- Directly from metals and action of HCl on metals.
2Na+Cl2→2NaCl
Zn+2HCl→ZnCl2+H2
- Action of HCL on metal oxide, hydroxide and carbonate.
CuO+2HCl→CuCl2+H2O
CaCO3+2HCl→CaCl2+CO2+H2O
Ca(OH)2+2HCl→CaCl2+H2O
- By precipitation of insoluble chlorides
AgNO3+NaCl→AgCl↓+NaNO3
Hg2(NO3)2+2NaCl→Hg2Cl2+NaNO3
Properties:
-Most chlorides are soluble except AgCl, Hg2Cl2 PbCl2and Cu2Cl2
-(But PbCl2 is soluble in hot water
-They are mostly thermally stable.
-Certain chlorides may sublimate on heating. Eg: NH4Cl
Nitrates:
Preparation:
- By action of HNO3 on metal, metal oxide, metal carbonate etc.
Zn+4HNO3→Zn(NO3)2+2NO2+2H2O
CaO+2HNO3→Ca(NO3)2+H2O
CaCO3+2HNO3→Ca(NO3)2+CO2+H2O
Properties:
-All metal nitrates are soluble except Bi(NO3)3which is insoluble.
-Alkali metal nitrates are decomposed as follows:
2NaNO3→2NaNO2+O2
2KNO3→2KNO2+O2
2RbNO3→2RbNO2+O2
(Except LiNO3)
4LiNO3→2Li2O+4NO2+O2
However, except above decomposition, all other decomposes as;
2Pb(NO3)2→2PbO+4NO2+O2
2Mg(NO3)2→2MgO+4NO2+O2
Except:
MetalNitrate→MetalOxide+NO2+O2
Hg(NO3)2→Hg+2NO2+O2
2Ag(NO3)→2Ag+2NO2+O2