Salts:

• When acid and base react form salts

• A metal replaces H+ ions in acids

Insoluble Salts:

• Insoluble salt prepared by precipitation reaction

• Soluble Salt + Soluble Salt ——> Insoluble Salt

  • Pb(NO3)2 + 2KI ———> PbI2 + 2KNO3

  • Lead Nitrate + Potassium Iodide ——> Lead Iodide + Potassium Nitrate

Solubility in Salts:

• Sodium, Potassium, Ammonia - All soluble, none insoluble

• Nitrates - All soluble; none insoluble

• Chlorides - Most are soluble; Insoluble: Silver, Lead(II)

• Sulfates - Most are soluble; Insoluble: Barium, Calcium and Lead(II)

• Carbonates - Most are insoluble; Soluble: Sodium, Potassium, Ammonia

• Hydroxides - Most are insoluble; Soluble: Sodium, Potassium, Ammonia, Calcium (partially soluble)

Hydrated & Anhydrous Salts:

• Salts with water in their structures are hydrated salts

• Salts without water in their structures are anhydrous salts

• Hydrated salt can be dehydrated to form anhydrous salts

• A compound with water is called a hydrated compound

Experiments:

Precipitation:

• For insoluble & soluble salts

• Process:

  • Add 2 insoluble salts in water and stir

  • pour through filter paper in a funnel

  • precipitate is formed

  • dry precipitate after the filter

Titration:

• For highly reactive metals

• Different methods to prepare salts of reactive metals as they form soluble bases

• Process:

  • definite volume of alkali in a conical flask using a pipette

  • add a drop of indicator

  • HCl filled burette

  • add acid to conical flask till color change

  • note the volume of acid added

  • repeat without indicator

  • heat till crystallisation

  • cool it, collect crystals, dry with filter paper

End of Chapter