A drop of oil with a volume of 0.004 mm3 spreads over the surface of the water

A drop of oil with a volume of 0.004 mm3 spreads over the surface of the water, forming a spot with an area of 400 cm3. Taking the thickness of the oil layer equal to the diameter of the oil molecule, find the diameter of the molecule.

Task data: V (oil drop volume) = 0.004 mm3 (0.004 * 10-9 m3); S (area of the formed oil spot) = 400 cm3 (400 * 10-6 m3); the thickness of the oil layer is equal to the diameter of the molecule.

You can find the diameter of an oil molecule using the formula: d = V / S.

Let’s calculate: d = 0.004 * 10-9 / (400 * 10-6) = 10 * 10-9 m (10 nm).

Answer: The calculated diameter of the oil molecule is 10 nm.