To Obtain The Crystals Of Blue Virtriol In Pure And Dry State From Bazzar Copper Sulphate. | Grade Xi
0Apparatus Required
- Evaporating dish
- Tripod stand
- Bunsen burner
- Wire gauze
- Glass rod
- Weighing balance
- Spatula
- Filter paper
- Funnel
Chemical Required
- Copper sulphate crystals (commercially available)
- Distilled water
Theory
Copper sulphate crystals, also known as blue vitriol, are often found in impure and hydrated form. This experiment aims to obtain pure and dry copper sulphate crystals from the commercially available hydrated form. The process involves crystallization, which is a method of purifying and obtaining a substance in a crystalline form by dissolving it in a solvent and then allowing it to recrystallize.
Process
- Weighing the Copper Sulphate Crystals:
- Weigh a clean and dry evaporating dish using a weighing balance.
- Transfer a small amount of copper sulphate crystals from the market sample into the evaporating dish.
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Record the mass of the evaporating dish and copper sulphate crystals.
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Dissolving the Crystals:
- Add a small amount of distilled water to the evaporating dish containing the copper sulphate crystals.
- Use a glass rod to stir the mixture until all the crystals have dissolved.
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Gently heat the solution using a Bunsen burner and wire gauze until all the crystals have dissolved.
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Filtering the Solution:
- Place a funnel fitted with a filter paper on top of a clean container.
- Pour the hot copper sulphate solution through the funnel and filter paper.
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Allow the solution to filter completely, collecting the filtrate in the container below.
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Crystallization:
- Place the filtrate in an evaporating dish and allow it to cool down slowly at room temperature.
- As the solution cools, the copper sulphate crystals will start to form.
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Stir the solution occasionally to promote the formation of larger crystals.
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Drying the Crystals:
- Once the crystals have formed, carefully decant the remaining solution from the evaporating dish.
- Transfer the crystals to a clean filter paper and allow them to dry completely.
- You can use a desiccator to accelerate the drying process.
Observations
- The copper sulphate crystals obtained from the market sample may be impure and have a greenish-blue color.
- Upon dissolving the crystals in water, the solution may appear cloudy or have a slight greenish tint.
- After filtration, the filtrate obtained is a clear and blue solution, indicating the removal of impurities.
- As the filtrate cools, small crystals of copper sulphate start to form and gradually grow in size.
- Once the crystals are dry, they appear as fine, blue, and well-defined crystals.
Observation Table
| Observation | Description |
|---|---|
| Initial Copper Sulphate Crystals | Impure and greenish-blue in color |
| Dissolved Copper Sulphate Solution | Clear and blue, with no visible impurities |
| Formation of Crystals | Gradual appearance and growth of blue copper sulphate crystals |
| Dried Crystals | Fine, blue, and well-defined crystals |
Calculations
The percentage yield of pure copper sulphate crystals can be calculated using the following formula:
Percentage Yield = (Mass of Pure Crystals Obtained / Initial Mass of Copper Sulphate Crystals) * 100
Results
The experiment successfully yielded pure and dry copper sulphate crystals from the commercially available impure sample. The crystals obtained were fine, blue, and well-defined. The percentage yield can be calculated using the formula provided above.
Precautions
- Always handle chemicals with care and wear appropriate protective gear, including gloves and eye protection.
- Be cautious while heating the copper sulphate solution, as it can splatter and cause burns.
- Allow the solution to cool slowly to promote the formation of larger crystals.
- Handle the dried crystals carefully to avoid shattering or breaking them.