Copper sulfate is an inorganic compound commonly found in pesticides used to kill bacteria, algae, plants, snails, and fungi. It is a mixture of copper oxide and sulfuric acid. It is also used to make blue crystals as a fun science experiment.
Steps
Method 1 of 3: Make a Copper Sulfate Solution
Step 1. Gather all your supplies
Put them in one place. Having all the equipment you need in one place will prevent you from having to stop in the middle of work to look for something.
- copper oxide
- sulfuric acid
- eye protection
- beaker
- Erlenmeyer flask
- spatula
- glass rod
- evaporation plate
- Bunsen burner
- tripod
- filter paper
- filtration funnel
Step 2. Organize your workstation
Place the Bunsen burner under the tripod that holds the beaker. Wear eye protection.
Step 3. Pour the sulfuric acid into the beaker
Heat the solution until it is about to boil.
Step 4. Add small pieces of copper oxide to the hot solution
Make sure to use the spatula so you don't burn yourself.
Step 5. Use the glass rod to stir the solution a little
You should not stir too vigorously or splash the hot solution on your skin. Stir for 30 seconds after adding each piece of copper oxide.
Step 6. Continue heating the solution after adding the last piece of copper oxide
You have to make sure that the chemical reaction occurs. This could take 1 or 2 minutes. The solution will appear cloudy and full of black powder.
Step 7. Turn off the Bunsen burner
You could use litmus paper to make sure there is no more acid in the solution. If acid remains, fumes will be produced after the solution has been filtered.
Step 8. Set the beaker aside
It's okay to let the beaker cool while you prepare for the filtration process.
Method 2 of 3: Filter the Copper Sulfate Solution
Step 1. Insert the filter funnel into the neck of the Erlenmeyer flask
Fold the filter paper to fit the funnel.
Polyethylene filter funnels are cheaper than glass ones. The diameter of the funnel should not be too large. Otherwise, the filtration will be unstable
Step 2. Check if it is safe to hold the beaker on top
If the glass is too hot, wait for it to cool down a bit more. The content will still be hot, so handle it carefully.
Step 3. Stir the solution in circular motions with the glass
Pour the solution into the filter funnel.
Step 4. Wait until the solution is filtered
You should end up with a blue, crystalline solution in the Erlenmeyer flask. If it still looks cloudy and black powdery, repeat the filtration process until it is crystal clear.
Method 3 of 3: Making Copper Sulfate Crystals
Step 1. Rinse the beaker
You will use this glass to make the crystals. Do not contaminate the filtered solution.
Step 2. Pour the blue, crystalline solution into the beaker
Be careful while doing it. The solution might still be hot enough to burn you.
Step 3. Leave the beaker in a warm place where it will not be handled for a week or longer
As the water evaporates, you will see crystals begin to form.
- This evaporative crystallization method could take a few weeks, depending on how hot the area is where you are storing the beaker. Crystals will start to form.
- You can also heat the solution over a Bunsen burner until half or two-thirds of the water has evaporated. Let the solution cool. This cold crystallization method is likely to form irregular crystals.
Warnings
Remember that copper sulfate is a harmful irritant. Do not ingest it. You should handle it with care and always wash your hands after touching it.