##### You can obtain a rough estimate of the size of a molecule by the following simpl

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You can obtain a rough estimate of the size of a molecule by the following simple experiment. Let a droplet of oil spread out on a smooth surface of water. The resulting oil slick will be approximately one molecule thick. Given an oil droplet of mass 1.4  10-6 kg and density 1490 kg/m3 that spreads out into a circle of radius 41.8 cm on the water surface, what is the order of magnitude of the diameter of an oil molecule?

May 25th, 2015

Oil will spread with height an molecule and will form a dish, a cilinder slice!
Data of problem:
Mdp=1.4^-6kg (mass of droplet)
Ddp=1490kg/m^3
Rdp=0.418m(converted from cm to m)

Formula of Density
Ddp=Mdp/Vdp and Vdp=Mdp/Ddp, where Vdp=volume of droplet

Vcl=(Rdp^2)*PI*h, where Vcl= volume of cylinder slice

Vdp=Vcl, so
Mdp/Ddp = (Rdp^2)*PI*h h=Mdp/[Ddp*(Rdp^2)*PI] , h is height of oil molecule.
Substituting values on equation...

Diameter = 1.4^-6/[1490*(0.418^2)*3.14]
= 1.713 x 10^-9 m

= 1.7 x 10^-9 m

May 25th, 2015

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May 25th, 2015
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May 25th, 2015
Dec 3rd, 2016
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