Describe how to prepare a pure sample of çalcium chloride in the laboratory
To prepare a pure sample of calcium chloride in the laboratory, follow these steps:
1. Weigh out the required amount of Calcium carbonate and place it in a beaker.
2. Gradually add hydrochloric acid to Calcium carbonate, stirring constantly until the reaction is complete.
3. Filter the resulting mixture using a filter paper to separate off any unreacted Calcium carbonate.
4. Heat the mixture obtained on a hotplate to evaporate the water in the mixture.
5. Once all the water has been evaporated, you will be left with Calcium chloride crystals. These crystals can be dried further by leaving them in an oven at a low temperature or under a heat lamp.
Your pure sample of Calcium chloride is ready for use. Store it in an airtight container until needed.
Here is a step-by-step guide on how to prepare a pure sample of calcium chloride in the laboratory:
1. Gather all the necessary materials and equipment, including calcium oxide (CaO) or calcium carbonate (CaCO3), hydrochloric acid (HCl), filter paper, beakers, glass stirring rod, Bunsen burner, tripod stand, wire gauze, and a weighing scale.
2. Start by measuring the required amount of calcium oxide or calcium carbonate needed to produce the desired amount of calcium chloride. Use the weighing scale to measure the appropriate amount accurately.
3. Place the measured calcium oxide or calcium carbonate into a clean and dry beaker.
4. Slowly add hydrochloric acid to the calcium oxide or calcium carbonate in the beaker while stirring continuously with a glass stirring rod. The reaction between calcium oxide or calcium carbonate and hydrochloric acid will produce calcium chloride.
5. Continue to add hydrochloric acid until the reaction stops, which is indicated by the absence of effervescence or the bubbling of gas.
6. Once the reaction has stopped, you will have a mixture of calcium chloride solution and any remaining unreacted calcium oxide or calcium carbonate.
7. To separate the calcium chloride from the mixture, set up a filtration system. Fold a filter paper into a funnel shape and place it in a funnel holder. Make sure the funnel is clean and free from any residues.
8. Carefully pour the mixture through the filter paper, allowing the liquid portion (calcium chloride solution) to pass through while retaining the solid portion (unreacted calcium oxide or calcium carbonate) on the filter paper.
9. Once the filtration is complete, rinse the beaker with a small amount of distilled water to ensure no traces of calcium chloride are left behind. Collect the rinse water in the same container as the calcium chloride solution.
10. Now, you have a filtrate containing a pure sample of calcium chloride. To obtain solid calcium chloride, you can either evaporate the filtrate or use alternative methods such as freeze-drying or vacuum drying.
Remember to handle hydrochloric acid with caution and always wear appropriate protective gear, such as gloves and safety glasses, during the experiment. Additionally, dispose of any waste materials according to the laboratory's guidelines and regulations.