Required Practical: Preparation of a Soluble Salt

Aim

To prepare a pure, dry sample of a soluble salt from an insoluble oxide or carbonate.

Apparatus

  • Measuring cylinder
  • 100 cm3 beaker
  • Spatula
  • Stirring rod
  • Conical flask
  • Filter funnel and filter paper
  • Bunsen burner
  • Tripod
  • Gauze
  • Heatproof mat
  • Evaporating basin
  • Watch glass

Method

1. Use a measuring cylinder to add 50 cm³ of sulfuric acid and add it to the beaker.

2. Heat the acid gently using a Bunsen burner.

3. Use a spatula to add small amounts of copper oxide to the acid and stir the solution using a glass rod until the base stops dissolving.

4. Filter the mixture through a filter funnel and filter paper to remove any excess copper oxide that has not reacted. Then, pour the filtrate, which is now copper sulfate, into a clean evaporating basin.

5. Place the evaporating basin on top of a water bath and gently heat the copper sulfate solution using a Bunsen burner until about half of the water has evaporated. This will cause the solution to become more concentrated.

6. Carefully pour the concentrated solution into a clean watch glass and leave it in a warm, dry place. As the solution cools, copper sulfate crystals will start to form.

It is important to handle all chemicals with care during the experiment, and to wear appropriate protective equipment such as goggles and a lab coat to avoid any accidents or harm. Also, do not heat the solution too quickly, as this can cause it to splatter which may result in injury.