science(chem)

posted by .

I have a question about compounds that oil out of solvents after drying.

How would I analyze this? Could I make a KBr pellet, or would I just be able to analyze it in UV spec?

I assume that the solvents used to dissolve the compound, would be used as a blank, right?

I tried to dry off the solvent used to dissolve the compound and it wouldn't completely dry off, and this is why I think it was oiling out of solution. I was originally planning on trying extraction after drying off the compound. I had no choice but to try to go and re-dissolve the compound in a solvent (CH2Cl2). It looked like it dissolved, but I'm not sure since the pasteur pipette looked as if it had an oily residue after I pipetted the solution over to another container....

Not sure what to do now,
Thank you

  • science(chem) -

    I have no idea what "oiling out of solution" means. Sure you can make a KBr pellet. AND you can run the sample on a UV. Can it be that part of the unknown dissolved in CH2Cl2 and the "oil part" was another compound? If I thought some had dissolved in CH2Cl2, I would attempt to recover the part that dissolved. That could be a pure component.

  • science(chem) -

    I dried a solution of solvent + unknown compound dissolved in it, and it would not fully evaporate off and leave a residue. What was left over no matter how much I heated the watchglass was stagnant droplets as if I was using dirty glass and I had poured a solution over it. (i.e. diry volumetric flask after pouring solution out, has stagnant droplets of water)

    I'm not sure if the oily substance was another compound. Hopefully it is not. I ran a plate and it showed 1 strong spot and 1 weak weak spot and my prof. said that it looks like it is one compound. This is the reason I tried to evaporate off the solvent and see if I could just see one compound or 2 after using this to spot another plate, therefore elminating the chance that it is solvent interaction that is causing the second spot.

    I will try to analyze the CH2Cl2 with the unknown in it and see what happens.

    Thank you Dr.Bob

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. science project

    I'm filling out forms for my freshmen science fair project and I'm not sure what they mean by this question: Data Analysis: Describe the procedures you will use to analyze the data that answer research question or hypothesis HELP! …
  2. science (chem)

    consider a sample that is a mixture of biphenyl, benzoic acid, and benzyl alchohol. The sample is spotted on a TLC plate and developed in a methylene chloride cyclohexane mixture. Predict the relative Rf values for the three components …
  3. science (chem) Rf values

    consider a sample that is a mixture of biphenyl, benzoic acid, and benzyl alchohol. The sample is spotted on a TLC plate and developed in a methylene chloride cyclohexane mixture. Predict the relative Rf values for the three components …
  4. Chemistry

    1. Water is a polar molecule. Therefore, it acts as a polar sollvent. a) Think about the following compounds: iodine, cobalt (II) chloride and sucrose (C12H22O11). Which compounds are soluble in water. b) Assume that the interaction …
  5. project Manangement

    Think of a recently completed group project that you have been involved in. This project may have been a student project, a group project, or an extracurricular project. Briefly describe the situation and choose one of the following …
  6. chem

    K2CO3 is an excellent drying agent for some classes of organic compounds. would it be a better choice for an acid (RCO2H)or an amine(RNH2)?
  7. science(chemistry)

    I have a question about solvent evaporation. If I had an organic layer and an aqueous layer in an unknown mixture of liquids and wanted to obtain the solid of a compound(s) dissolved in the layers, is it reasonable to assume that I …
  8. chem

    Hey could you please help me. Why would K2CO3 be a better drying agent than Na2SO4 when drying out water from clohexanol?
  9. Science

    In general, what would a scientist do after forming a testable question?
  10. Science

    In general, what would a scientist do after forming a testable question?

More Similar Questions