C5.6 Making a salt from a metal carbonate

• Metal carbonates are generally insoluble in water (except the carbonates of the Group 1 metals, such as sodium carbonate)
• Step 1

  Add powdered insoluble reactant to acid in a beaker, one spatula at a time stirring to mix. Continue adding powder until it is in excess (some unreactive powder is left over)
• Step 2

  Filtrate the mixture in the beaker to remove the excess powder. Collect the filtrate
• Step 3

  Pour the filtrate into an evaporating basin. Place on a water bath, and hear until about half the water from the solution has been removed by evaporation. Stop heating when small crystals start to appear around the edge of the evaporating basin
• Step 4

  Pour the remaining solution into a watch glass, and leave in a warm, dry place for crystallisation to occur
• Step 5

  If necessary, dry the crystals by dabbing gently with filter paper
• Safety precautions

  Use dilute hydrochloric acid

  Do not touch hot apparatus

  Tie back hair and loose clothing

  Wear eye protection