Question

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Can u plzz explain Molecular layer method by giving oleic acid example.

I want verified answer☑️✅

plzz explain me clearly.


1cc of oleic acid is put into 400cc of alcohol.
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Answer 1

Answer:

Measuring the diameter of a molecule or the diameter of an atom comes under measurement of very small distances.

Here, We need to find the diameter of a molecule of oleic acid.

This is done by forming ka monomolecular layer of organic acid on water surface.

The steps to do so are :

➸ Dissolve 1 cm³ of oleic acid in 20 cm³ alcohol resulting in 20 cm³ of the volume of the solution.

➸ Take 1 cm³ from the solution made.

➸ Dilute it with 20 cm³ alcohol again.

➸ The concentration of the solution of oleic acid now is : 1/(20*20) cm³.

➸ Take any amount of water in a beaker.

➸ Now, sprinkle lycopodium powder on the surface of water

➸ Put one drop of the solution formed of oleic acid on the water.

➸ The particles of lycopodium powder are very small in size, hence, it would help the drop to stay on water surface.

➸ The drop will stay at the surface of the water and it will start spreading.

➸ It would spread into a thin layer of solution above the surface of water.

➸ We have to measure the diameter of the film (thin layer) formed.

➸ Now, We assume "n" as the number of drops dropped on the surface of the water.

➸ Hence, the Volume of n drops will be nV cm³.

➸ Now, We already know the concentration of oleic acid solution we formed that is 1/20*20 cm³. Hence, the amount of oleic acid = nV * (1/20*20) = nV/20*20 cm³.

➸ Now, We assume the thickness of the film as t, area as A. Hence, the thickness of the film = Volume/Area.

➸ Hence, thickness = nV/20*20A cm = nV/400A cm.

➸ After solving by this formula, we get the answer as 10^{-9} m.