Leakage problem in the separatory funnel
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When measuring copper in accordance with the national standard HJ485-2009, liquid leaks out during color development and extraction, usually from the plug on the separatory funnel and the piston in the middle. I would like to know what the reason for this is. Shake the separatory funnel with water; it’s fine, no problem. In the earlier steps of color development extraction, it’s fine to shake the solution; but once carbon tetrachloride, the extractant, is added, bubbling can be heard at the junction where the liquids meet upon shaking, and both the plug and the piston start leaking liquid. Also, why is there a hole on the neck of the separatory funnel? Is it to make it easier to remove the stopper? But that would also cause leakage, right? Ugh!
Just shake it a few times and release some air in reverse; also make sure to apply Vaseline properly, secure the stopper with an rubber band, and press it tightly when covering it – it usually won’t leak
That hole is for venting. It is estimated that the leakage is caused by excessive gas pressure inside the funnel; start by shaking it a few times less often, and regular deflation should resolve the issue.
The reaction might be a bit intense; shake it fewer times and then release air, repeat this process several times, and then there will be no problem.
Vaseline, when dissolved in carbon tetrachloride, will definitely leak; try using silicone grease to see if that works.
On the fifth floor, it was said that Vaseline is dissolved by carbon tetrachloride. During the experiment, would a cock that has just been coated with oil dissolve at such a fast rate?
Coat the seal area with vacuum silicone grease
Use a funnel with PTFE seals; I even use PTFE seals on my titrators. It’s not because of leakage – it’s just that I hate the contamination caused by vaseline
Try using a different sealant.
I encountered this issue while measuring zinc as well; I tried releasing more gas, but there was still leakage. It would be better to modify it to make a few gentle oscillations.
Reply to 10# zhang Xiaoling: If there is less oscillation, the extraction effect might not be very good