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Laboratory Apparatus question

  1. Dec 23, 2004 #1
    What piece of apparatus can be used to introduce more liquid into a reaction and also serve as a pressure valve?

    c)thistle tube

    I'm guessing it's the retort. Am I correct? If not can you tell me which one. Thnks...
  2. jcsd
  3. Dec 23, 2004 #2


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    You might want to check the definitions of these articles.

    A retort is simply a vessel with an outlet tube, typically used for distillation, sublimation, or decomposition by heat.

    A pinchcock is a clamp used to regulate or close a flexible tube, especially in laboratory apparatus.

    A stopcock is a valve that regulates the flow of fluid through a pipe, but it does so by being rotated to open and closed, so doesn't regulate pressure very well.

    A thistle tube is simply a thin tube usually with a larger diameter bulb at one end.
  4. Dec 23, 2004 #3
    Thanks, how do find out about these stuff? So i guess the answer is the pinchcock then?
  5. Dec 24, 2004 #4


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    Chemistry resources

    Well, I did chemistry a long time ago, so I am somewhat familiar with laboratory apparata (and I had my own chemistry set), and

    one can use hard-copy or on-line dictionaries (e.g. www.dictionary.com), or scientific encyclopedias, and if either of those don't work, I just use google and search for key works, like the names of objects you mentioned, which in the case of the thistle tube, lead me to a manufacturer of glass-ware.

    Also, IUPAC - International Union of Pure and Applied Chemistry - ( http://www.iupac.org/index_to.html [Broken] ) has on-line resources.

    Best wishes in your studies.
    Last edited by a moderator: May 1, 2017
  6. Dec 29, 2004 #5
    Look for Vogel's "Practical Organic chemistry" I downloaded it using Lizard tech deje-vu as a reader. I found that there is an Adobe version also. If I can locate the link I will post it. It has a great wealth of lab set-up information along with diagrams of the apparatus.
  7. Dec 29, 2004 #6


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    In another thread you posted a question about the Thistletube. Perhaps you need to review the lab appartus you described in that question, and ask yourself what is the purpose of the Thistletube.
  8. Dec 29, 2004 #7
    The problem is I DIDN'T know what the purpose of the thistletube was... my teacher does not do lab work with apparatuses such as that and pinchcock.... In fact we only do at most 20-30% of the lab works needed for the exam.
    And besides, i posted this question up before the other one. O ya, and thanks for your reply integral, i think i understand it now.
    Last edited: Dec 29, 2004
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