Question

In an experiment to estimate the diameter of an oil molecule, an oil drop of diameter 0.05cm spread over a circular patch whose diameter is 20cm.
Determine:

1. The volume of the oil drop. 
2. The area of the patch covered by the oil. 
3. The diameter of oil molecule. 
4. State one assumption made in the statement above. 
5. Three possible sources of error in this experiment.

Answer 1

1. Volume = ⁴/₃Πr^{3
   4}/₃ x ²²/₇ x 0.025³ 
   =6.548 x 10^-5 cm³
    
2. ²²/₇ x 10²
   =314cm²
    
3.  Area x diameter of the molecule = vol
   Diameter of the molecule= 
   6.548 x 10^-5
         314
   =20.09 x 10^-7cm
    
4.   
   • Oil drop is spherical
   • Oil patch is a monolayer
5.    
   • Getting right oil
   • Measuring drop diameter
   • Measuring diameter of the oil patch
   • Getting a drop of the right size