How Does Oil's Behavior on Water Demonstrate Molecular Structure?

[Aleksandar]

The question says:
Suppose that oil consists of molecules of CH2. This means that 1 mol of oil, consisting of 6.02x10^23 molecules, has a mass of 14g. One mililiter of oil has a mass of of 0.95g. When this much oil is poured on water, it does not spread forever but spreads unti it makes a circular film of area 1.5x10^7 cm^2. How does the fact that the oil does not spread forever support the idea of atoms and molecules? Assuming that the oil slick is one molecule thick, with the molecules touching, and the molecules are spheres, ESTIMATE THE SIZE OF AN OIL MOLECULE.

PLEASE HELP! I need answer of the question, as well as how to get to the answer.

Thank you guys in advance

 

[Andrew Mason]

The question says:
Suppose that oil consists of molecules of CH2. This means that 1 mol of oil, consisting of 6.02x10^23 molecules, has a mass of 14g. One mililiter of oil has a mass of of 0.95g. When this much oil is poured on water, it does not spread forever but spreads unti it makes a circular film of area 1.5x10^7 cm^2. How does the fact that the oil does not spread forever support the idea of atoms and molecules? Assuming that the oil slick is one molecule thick, with the molecules touching, and the molecules are spheres, ESTIMATE THE SIZE OF AN OIL MOLECULE.

PLEASE HELP! I need answer of the question, as well as how to get to the answer.

Thank you guys in advance

How many molecules are in the 1ml oil film? What is the no. of molecules/unit area? What is the area occupied by one molecule?

AM

 

[Aleksandar]

That is the question. I don't know, it wasn't stated in the question.

 

[Andrew Mason]

That is the question. I don't know, it wasn't stated in the question.

?? You are expected to figure it out! Just ask yourself the first two questions I posed: 1. how many molecules in .95 grams (ie. .95/14 moles)? That is the number of molecules spread over the given area. 2. How many molecules per unit area? (divide the answer in 1. by the area)

AM

 

[Aleksandar]

Well, I got 4.085x10^22 molecules, and when I divided with the area, I got 2.723x10^15. Is that my final answer??

 

[Andrew Mason]

Well, I got 4.085x10^22 molecules, and when I divided with the area, I got 2.723x10^15. Is that my final answer??

What does your answer mean? You have to actually apply some independent thinking to the question! If that many molecules take up that much area, how much does one take up?

AM