Question

A small drop of oil has a volume of 5 x 10^-8m³. When it is put on a surface of some clean water, it forms a circular film of 0.1m² in area.

1. What is the size of a molecule of oil 
2. State 2 assumptions you made in your calculations

Answer 1

1. Volume of drop = 5 x 10^-8 m³
   Area of circular film = 0.1m²
   V = A x H
   h=VA 
   Size of molecule=5 x 10^-8m/20.1m²
   =5.0 x 10^-7m
2.    
   • Atoms are spherical 
   • Mass uniformly distributes