A mono layer of poppy-seed The same in a 2-ml
syringe
Experiment
Mol 8How small are molecules? A model
of the oil drop experiment:
Oil drop experiment:
When an exactly measured volume of oil (dissolved in petrol) is brought
on a water surface it substance will spread out until it is only one molecule
thick ("monomolecular layer"). The surface of the layer is measured.
Dividing the volume V by the surface F results in the
diameter (V/F) of the molecules.
You may reproduce the idea behind this experiment
by taking poppy-seed as model of oil:
* Measure the volume of poppy-seed in a 2-ml measuring cylinder.
* Distribute it in a dish making a layer as a thin as possible.
* Calculate the area F from the diameter of the poppy corns
in the dish.
* Divide the volume of poppy-seed [1.8
cm3]=[1800 mm3] by their
surface [2829 cm2] to obtain
the thickness [0.6 mm] a single corn.
* Control your measurement and calculation by a direct measurement
of a corn.