Question

a drop of olive oil of radius 0.30 mm spreads into a nearly circular film of radius 12 cm on the water surface. estimate the molecular size of the olive oil

Answer 1

Answer:

2.5 x 10^-9 mm

Step-by-step explanation:

Given in the question that,

radius of drop of olive oil = 0.30 mm

radius which it made on the surface = 12 cm

Step 1

conversion from cm to mm

1 cm = 10mm

12 cm = 120mm

Step 2

Since olive oil spread as a film on the surface so suppose it is 1 molecule thick on water surface, then the thickness of the film will give the estimate of diameter of molecule

diameter = Volume of oil drop / Area of film

= 4/3 π (0.03)³ / π (120)²

d = 4/3 (0.000027) / 14400

d = 0.000036 ÷ 14400

d = 2.5 x 10^-9 mm