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Short & simple viscosity question

  1. Apr 13, 2008 #1
    I've managed to calculate the viscosity of glycerol to be about 1.9 P. Google says it's supposed to be 1.5. Could I say that evaporated water has caused the glycerol to become more viscous than it should be? (It could just be a thicker glycerol but I'm just looking things to blab on about)
    Basically: Does water evaporate from glycerol and if so does it make it more viscous?
  2. jcsd
  3. Apr 13, 2008 #2


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    What's your calculation?
  4. Apr 14, 2008 #3
    It's abit lengthy and I'm pretty sure it's right, I just need to know whether water evaporates from glycerol if you leave it out without a lid.
  5. Apr 14, 2008 #4

    Andy Resnick

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    Try it- put some in a watch glass, see what happens.

    Have you measured the density? What temperature did you do the viscosity measurement at? What are your error sources?
  6. Apr 14, 2008 #5
    The density was given as 1200 kg m-3, temperature was an average of 21 degrees C. My only error source is parrallax error. But my % error was 10.7%. I can't really try it but I'll mention the watch glass thing in my evaluation, thanks.
  7. Apr 15, 2008 #6


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    Water actually absorbs into most alcohols if the alcohol is left in the air however I'm not quite certain if this the case with glycerol. Water makes a lot of substances more viscous especially if it can hydrogen bond with the other species. In this light water probably absorbed into your glycerol and caused it to become more viscous.
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