lihyuan:

ACIDS, BASES & SALTS
Properties of acids

-Sour taste
-Turns blue litmus paper red
-pH<7
-Produces H+ in water
-Acid + carbonate -> salt + water + carbon dioxide
-Acid + reactive metal -> salt + hydrogen
-Acid + alkali -> salt + water only –neutralization reaction
Acid + base -> salt + water only

Properties of alkali
-Bitter taste
-Turns red litmus paper blue
-pH>7
-Produces OH- in water
-Alkali + ammonium salt -> salt + ammonia gas + water
-Alkali + acid -> salt + water only

Types of oxides

-Amphoteric; show both acidic & basic properties.
only PbO, Al2O3 & ZnO.

-Basic; metallic oxides.
e.g. Na2O, CuO, MgO, CaO.

-Acidic; non-metallic oxides.
e.g. CO2, SO2, SiO2.

Neutral; only contain carbon, hydrogen, nitrogen & oxygen.

Preparation of insoluble salts
-usually through precipitation

NITRATES All soluble.

CHLORIDES All soluble except AgCl & PbCl2.

SULPHATES All soluble except BaSO4, PbSO4.

CARBONATES All INSOLUBLE except SPA.
Sodium, Potassium & Ammonium carbonate.