Salt Preparation

• Adding Excess

  • used to prepare salts that are soluble in water except salts that contain group 1 metals (very reactive)

  1. add excess solid to the acid in a beaker one spatula at a time, stir to mix the solid and acid well, add until some of the solid does not react
  2. filter the mixture in teh breaker to remove the unreacted solid, collect the filtrate which contains the salt solution
  3. heat the salt solution to obtain a saturated solution
  4. allow saturated solution to cool and form salt crystals. Wash crystals with cold distilled water and dry between sheets of filter paper
• Titration

  • used to prepare salts that contain group 1 metals or ammonium salts
  • a titration is carried out to determine the volumes of acid and alkali or carbonate that should be mixed to obtain a solution containing only salt and water
  • the acid or alkali or carbonate are mixed together using the volumes determined by the titration, salt is obtained from reaction mixture by crystallisation
• Precipitation

  • used to prepare insoluble salts
  • a precipitate is an insoluble salt formed when the two solutions are mixed
  • a precipitation reaction involves the formation of a precipitate when two solutions are mixed
  • a nitrate salt and a salt containing sodium or potassium ion (e.g. lead nitrate and potassium chloride)

  1. mix the two solutions together
  2. filter to collect precipitate as the residue
  3. was with cold distilled water to remove impurities
  4. dry between a few sheets of filter paper