Size of Oil Molecule

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When droplet of olive oil (oleic acid) is placed on water, oil spreads out until oil layer is 1 molecule high.

If the oil “spill” radius and the size of theĀ original droplet can be measured, one can estimate the length of the oil molecule.

Volume of original droplet = volume of oil spill pancake.

Use wire loop (diameter~1mm), to estimate volume of droplet (assume droplet is wafer, not sphere). Use calipers to measure.

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Dip loop in olive oil.

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Remove excess oil using paper towel.

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Dust surface of water with lycopodium powder. This allows you to see clearly the final diameter of the spill. The larger the container the better.

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Dip tip of wire loop into water. Oil immediately spreads out to form circle (very cool to watch!).

Measure diameter with ruler.0329171623

Should get order-of-magnitude accuracy.

  • Lycopodium powder and oil located in L35, corrosive materials cabinet (powder is safe to handle).
  • Tub located in L35.
  • Calipers located in L35, section D-2.
  • Tape measure in L35, section A-1.