Materials:
- Mixture of ammonium chloride and potassium chloride
- Distilled water
- Beakers or flasks
- Heating source (e.g., hot plate or Bunsen burner)
- Thermometer
- Filter paper
- Funnel
- Ice bath
Procedure:
1. Prepare the Solution:
- Weigh a known amount of the mixture of ammonium chloride and potassium chloride.
- Add distilled water to the mixture to dissolve the salts.
- Heat the solution gently while stirring until all the salts are dissolved.
2. Crystallization:
- Allow the solution to cool slowly at room temperature.
- As the solution cools, the less soluble salt (ammonium chloride) will start to crystallize.
- Keep the solution undisturbed to allow for proper crystal formation.
3. Cooling and Crystal Separation:
- Once the solution reaches room temperature, place it in an ice bath to further reduce the temperature.
- This additional cooling will promote further crystallization of ammonium chloride.
- Leave the solution in the ice bath for some time to ensure complete crystallization.
4. Filtration:
- Set up a filtration apparatus with filter paper placed in a funnel.
- Pour the chilled solution carefully into the funnel.
- The crystals of ammonium chloride will be retained on the filter paper, while the potassium chloride remains dissolved in the solution.
5. Washing:
- Wash the crystals on the filter paper with a small amount of ice-cold distilled water.
- This step helps remove any remaining potassium chloride.
6. Drying:
- Transfer the crystals from the filter paper to a watch glass or Petri dish.
- Place the watch glass or Petri dish in a warm, dry place or use a gentle stream of warm air to dry the ammonium chloride crystals.
7. Final Product:
- After drying, you will have isolated and separated the ammonium chloride crystals from the mixture.
By following these steps, you can successfully separate ammonium chloride from a mixture of potassium chloride through fractional crystallization.
