InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
A drop of olive oil of radius 0.25 mm spreads into a circular film of radius 5 cm on the water surface. Estimate the molecular size of the olive oil |
|
Answer» Area of the film, `A=pir^2cm^2` `=25 pi cm^2` [`because` Radius of the film, r=5cm] Volume of the drop, V=`4/3pi "(Radius of oil drop)"^3` `=4/3xxpixx(0.25 mm)^3` `=4/3xxpixx(2.5xx10^(-1))^3 mm^3` `=4/3xxpixx15.6xx10^(-3)mm^3` `=4/3xxpixx15.6xx10^(-6) cm^3` Molecular size = Thickness of the film `=V/A` `=(4pixx15.6xx10^(-6))/(3xx25pi)` `=0.83xx10^(-6)` cm `=8.3xx10^(-9)` m |
|