explain how you can obtain pure samples from a mixture containing ammonium chloride,copper(ii)oxide and potassium carbonate
To obtain pure samples from a mixture containing ammonium chloride, copper(II) oxide, and potassium carbonate, you can follow a series of steps:
1. Dissolve the mixture in water: Add a suitable amount of water to the mixture to dissolve the components. Ammonium chloride is highly water-soluble, whereas copper(II) oxide and potassium carbonate are insoluble or have limited solubility in water.
2. Filter the solution: Once the mixture is dissolved, you need to separate the insoluble components, copper(II) oxide, and potassium carbonate from the solution by filtration. Using a funnel and filter paper, pour the mixture into the funnel, allowing the liquid to pass through while retaining the solid residue.
3. Wash the residue: Wash the residue on the filter paper with a small amount of water to remove any remaining soluble impurities. This step helps to obtain a purer sample.
4. Dry the residue: Carefully remove the filter paper with the residue from the funnel and place it in an oven or a suitable drying apparatus to completely dry the sample. Make sure to set the appropriate temperature to avoid decomposition or melting of the substances.
5. Separate copper(II) oxide: Once dry, carefully separate the copper(II) oxide from the filter paper. You can scrape it off or gently brush it into a clean container. This should give you a sample of pure copper(II) oxide.
6. Obtain ammonium chloride: The filtrate collected during the filtration step contains dissolved ammonium chloride. To obtain a pure sample of ammonium chloride, you need to evaporate the water. You can do this by pouring the filtrate into a shallow dish or beaker and allowing the water to evaporate at a low temperature. As the water evaporates, ammonium chloride crystals will form.
7. Collect potassium carbonate: As potassium carbonate is also water-soluble, it will be present in the evaporated solution along with ammonium chloride. To separate potassium carbonate, you can perform a process called recrystallization. Dissolve the solid residue obtained after evaporation in a minimum amount of hot water, stirring until the solution is saturated. Allow the solution to cool slowly, and potassium carbonate crystals will form. Filter the solution again to collect the pure potassium carbonate crystals.
By following these steps, you can obtain pure samples of ammonium chloride, copper(II) oxide, and potassium carbonate from the initial mixture.