7.2: Thin-Layer Chromatography - Pre-lab

Organic Chem I, Laboratory Manual , Chem · LibreTexts

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    Name: ____________________ Date: ____________________

     

    1.   A student conducted an experiment using the silica gel TLC plate shown below by spotting a sample of MidolTM, caffeine, and acetaminophen on the plate and eluting with petroleum ether: chloroform (9:1, v/v).

    clipboard_e98bb7ff15f1d064e4d80203e69922930.png

    a. What are the Rf value of acetaminophen and of caffeine, respectively?

    b. Based on this TLC analysis, what are the ingredients in a tablet of MidolTM?

    c. Which one is more polar, caffeine or acetaminophen?

    d. Another student accidentally used MidolPM in his experiment and observed only one spot. Speculate as to which spot was absent and explain.

    2. Why must the spot be applied to the TLC plate above the level of the development solvent?

    3. What will be the result of adding too much sample to the TLC plate?

    4. Why must a pencil be used for drawing the lines and spotting?

    5. Describe what an iodine vapor chamber is and explain how it works?

     

    This page titled 7.2: Thin-Layer Chromatography - Pre-lab was last modified on Sun, 09 Aug 2026 00:53:38 GMT and is shared under a CC BY 4.0 license and was authored, remixed, and/or curated by Saadia Khan.