Required Practical 1

Aim

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

Materials Needed

• Insoluble oxide or carbonate (e.g., copper oxide or calcium carbonate)
• Dilute acid (e.g., hydrochloric acid or sulfuric acid)
• Bunsen burner
• Heat-resistant glass beaker
• Glass stirring rod
• Water bath or electric heater
• Filter paper
• Funnel
• Evaporating dish
• Tripod stand with wire gauze
• Safety goggles and lab coat (for safety)

Procedure

1. Safety Precautions
   1. Wear safety goggles and a lab coat to protect your eyes and clothing from potential hazards during the experiment. Work in a well-ventilated area to prevent the buildup of harmful fumes.
2. Prepare the Dilute Acid Solution
   1. Measure the appropriate volume of dilute acid (e.g., hydrochloric acid or sulfuric acid) using a graduated cylinder. Add the acid to the heat-resistant glass beaker.
3. Add the Insoluble Oxide or Carbonate
   1. Carefully add the insoluble oxide or carbonate (e.g., copper oxide or calcium carbonate) to the dilute acid in the beaker. Use a glass stirring rod to gently mix the contents and ensure complete reaction.
4. Heating with a Bunsen Burner
   1. Set up the Bunsen burner on a heat-resistant surface with a tripod stand and wire gauze. Place the beaker containing the acid and insoluble oxide or carbonate on the wire gauze. Adjust the height of the Bunsen burner flame to provide gentle heating.
5. Evaporate the Solution
   1. Heat the mixture in the beaker using the Bunsen burner until the acid reacts completely with the oxide or carbonate. This will produce a soluble salt and water. Continue heating to evaporate the excess water, leaving behind a concentrated salt solution.
6. Filter the Solution
   1. Allow the solution to cool down slightly. Set up a funnel with filter paper on top of an evaporating dish. Pour the hot solution into the funnel to separate the insoluble impurities from the soluble salt solution. The soluble salt solution will pass through the filter paper into the evaporating dish.
7. Evaporate the Solution Further
   1. Place the evaporating dish containing the salt solution on a water bath or an electric heater. Gently heat the solution to further evaporate the water. Be cautious not to overheat, as it may cause the salt to decompose.
8. Drying the Sample
   1. Once most of the water has evaporated, remove the evaporating dish from the water bath or electric heater. Allow the dish to cool and the remaining water to evaporate, leaving behind a pure, dry sample of the soluble salt.
9. Record Your Observations
   1. Record your observations throughout the experiment, noting any colour changes, gas production, or other changes that occur during the reaction.
10. Clean Up
    1. Dispose of any waste materials properly and clean all equipment used in the experiment. Put away the chemicals and ensure the work area is left clean and safe.

Conclusion

By following this procedure, you can successfully prepare a pure, dry sample of a soluble salt from an insoluble oxide or carbonate using a Bunsen burner to heat dilute acid and a water bath or electric heater to evaporate the solution. Always exercise caution and follow proper safety procedures while conducting the experiment.