Copper Conversion Tips and Hints
Part A:
This is simply a reaction between copper and nitric acid. The copper turnings need to be in contact with the nitric acid. To achieve this, cut the turning into smaller pieces so they lay flat in the beaker. This reaction should be done in the fume hood. The Acid can be simply added drop wise, (10-15 drops per ml). As you go back to check on your beaker, you may add additional nitric acid. you should have enough liquid so that you can swirl the acid around mixing with the copper. You will also see a dark brown gas evolve if your reaction is going fast.
Make sure you use Distilled water. Remember, the copper is the limiting factor so the amount of water really does not matter. It is simply the solvent.
Part B:
Add your 10mL of water, as directed. (End day 1)
***Sodium Hydroxide is drain cleaner. Dissolved human flesh. It is fairly concentrated. Use with caution.***
To determine if you still need more base to precipitate. Let the solution settle so you can look through the clear part of the solution. Add a drop and look carfully to see if that drop causes additional solid torm. Your instructions indicate to test your pH of your solution. If you have no more precipitation then you are going to be basic. I would suggest skipping the pH paper, and just make sure your base is no longer precipitating. If in doubt, add a little more base.
Part C:
Heat your substance on the hot plate until it turns black. Do NOT boil for 3 min as the instructions indicate. Once it turns black you are done (End Day 2)
Start your filtration,
- if you don't remember how to filter, you need to watch the video. Any on the fly questions, please ask.
- You do NOT need to weigh filter paper.
- You will be washing the CuO with water after you are done. You do NOT have to use hot disstilled water, just use plain room temperature disstilled water.
- To wash simply means to add additional water to filter and suck the clean water through. Bringing any dissolved ions with it.
- Discard filtrate: Filtrate is stuff that went through the filter. Remove bottom flask and dump it down the drain.
- You do not need a clean beaker... simply rinse old one and re-use afte part D is done.
- Put funnel back on to the flask and start part D.
Part D:
You will be converting the CuO to Copper Chloride. FYI: Copper (I) Chloride is lime green and Copper (II) Chloride is sky blue.
Things to remember:
- You will be adding your HCl drop wise to the filter. As the copper chloride is produced it will get sucked through the filter. The filtrate is our new substance.
- I use the distilled water squirt bottle to blow water into the corners of the filter paper to break up the CuO. The use the HCl drop wise.
- You will not be needing a new clean beaker. Just use the side armed flask. In the end, dump your Copper nitrate back into your beaker and place it on the center table.
- You man not be able to filter today due to the fact that there are only so many sinks. With that said, use your time wisely. Work on your videos and or work on your powerpoint. (End day 3)
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Part E.
You will be converting your copper compound to copper (II) phosphate.
Things to remember:
Addition of acid and base
- Merky means solid is forming. It might disappear as you stir, this means you are close to neutral.
- Keep in mind, every drop of acid you added in the last step will require a drop of base in this step.
- Do NOT test pH, simply follow acid base nutrualization rules for removing solid(merky).
- If it is still acidic, just add a drop or two of your base. Just make sure there is not solid in your beaker.
Addition of sodium phosphate
- add your Na3PO4, and then add it drop wise until stops precipitating.
- End day 4
Filtering out your sodium phosphate:
- Do not heat your solution (as indicated in your lab). Simply filter.
Part F: Preperation of Copper sulfate
- Once again you will react the solid copper phosphate in the filter. Using Sulfuric acid(2M).
- When you add your sulfuric acid don't worry about measuring quantity. Add drop wise until all copper solid is reacted.
- do not turn on suction until acid has had a chance to react.
- Add zinc. Let react over night.
- End day 5
Part G: Preperation of Copper. (These instructions will replace workbook)
Removing excess zinc... Likly you will have excess zinc. I prefer to use the 6M HCl to remove zinc.
- Weigh filter paper
- filter out copper/zinc solution
- With only solid zinc and copper in bottom of filter. Turn off suction and add 10 drops of HCl
- Inspect for bubbling. Zn + HCl => H2(g) and ZnCl2(aq) the bubbles are hydrogen gas.
- If no bubbling then you are done. Be aware if there was no zinc then you might still have Cu2+ dissolved. Inspect for blue color. Add more zinc inorder to remove if time allows.
- After zinc bubbles away ( add more HCl to increase rate of bubbleing) Wash with distilled water several times.
- remove filter fold in half to shelter copper from atmosphere and let dry. Note: Copper will immidiatly start to react with the atmosphere creating CuO which is black. We will have to allow for some of this to be in our sample at the end. Hard to stop. . End Day 6
- Weigh dried paper End Day 7
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