Pls explain this paragraph tell the relationship bt intermolecular forces and vapour pressure

Dear student,

The vapor pressure of a liquid is the equilibrium pressure of a vapor above its liquid/solid, i.e., the pressure of the vapor resulting from the evaporation of a liquid/solid above a sample of the liquid/solid in a closed container.
This means if a liquid is quickly evaporated then the vapor pressure of that liquid is very high. 

Intermolecular forces are the attraction forces between the molecules and these forces join the molecules. If there is a strong intermolecular force then it is very difficult to break the bonds between the molecules, so if the bond is not broken easily then it will not get evaporated easily. Hence, it will have a low vapor pressure.

So, we can say that vapor pressure is inversely proportional to the intermolecular forces.

Water is having a strong intermolecular force of attraction because of the presence of hydrogen bonds. And due to strong intermolecular forces of attraction, its vapor pressure is low.

Ethanol is also a polar molecule but it is less polar than water because ethanol cannot form hydrogen bonds between its molecules, so there are weak forces of attraction between the molecules and hence there will be more vapor pressure as compared with water.

Diethyl ether is essentially nonpolar, so they have very little force of attraction between their molecules and hence have a maximum vapor pressure.

Regards

 

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