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Slick to the touch

  1. Apr 26, 2006 #1

    Ouabache

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    I have noticed that (sodium hydroxide) NaOH solution and also bleach (active ingredient: sodium hypochlorite), soap and oils are all slippery to the touch.. Why is that so? What propertie do they share that allow them to behave this way?
     
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  3. Apr 27, 2006 #2

    Astronuc

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    I would imagine low intermolecular forces resulting in low shear forces, and they fill in the 'valleys' of a surface. Basically that's how a lubricant works.
     
  4. Apr 27, 2006 #3
    Anything that is basic is usually slippery
     
  5. Apr 27, 2006 #4
    NaOH basically turns some of your skin cells into soap through a saponification reaction. I'm not sure about other bases though.
     
  6. Apr 27, 2006 #5

    mrjeffy321

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    Ya, I was going to say, it could be due to the NaOH (or more specifically, the OH- ?) reacting with the oils/fats in your skin making a thin layer of soap which gives it the slippery texture.
     
  7. Apr 28, 2006 #6

    Ouabache

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    Thanks for all you ideas; the low intermolecular forces (for why oils or lubricants are slick) and also the saponification of base with skin oils.. I suspect that is what happens with bleach too (NaOCl) although its pH is not as high as sodium hydroxide.. It is still basic (ph = 9-10) and may be enough to enable the reaction.
     
  8. Apr 28, 2006 #7
    Yeah, NaOH solutions do feel slippery, I noticed that too. I suggest keeping your hands out of them.
     
  9. Apr 29, 2006 #8

    Gokul43201

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    I think it is the Na+ that is specifically relevant to the soapy feeling (and the basic medium). The "soap" is after all the sodium salt of the fatty acid (of course, another alkali, K+ say, would do this too). That's probably why the same thing happens with bleach.
     
    Last edited: Apr 29, 2006
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