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Are there any other colligative properties other than lowering of vapor pressure, osmotic pressure, boiling point elevation, and freezing point depression? I was wondering whether surface tension of an aqueous solution is colligative or not, but I mostly think it should be. Can anyone help?

Edit: I am pretty aware of what a colligative property is. It's a property's of the solution that doesn't depend on the nature of solute, rather only concentration of the solute, and the nature of solvent.

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Firstly I would like to expand a bit on what a colligative property is, in order to bring more understanding and also be able to apply this to a named physical property.

Colligative properties depend mainly on the number of particles in a solution.

The values of the colligative properties are approximately the same for equal concentrations of different constituents in solution regardless of the species or chemical nature of the constituents. Examples are osmotic pressure, vapor pressure lowering, freezing point depression, and boiling point elevation (as you have noted).

Furthermore, physical properties of substances are not just limited to the colligative nature. In fact a number of properties have been defined:

  • additive (depend on the total contribution of the atoms in the molecule or on the sum of the properties of the constituents in a solution e.g molecular weight).

  • constitutive (depend on the arrangement and partly on the number and kind of atoms within a molecule e.g interfacial characteristics).

  • other thermodynamic physical properties are known (extensive, intensive)


Having gained this background, it is now evident that surface tension (a force that pulls the molecules of the interface together) is dependant on the arrangement and also on the nature of atoms or molecules , therefore is more of a constitutive property rather than a colligative property.

I have included a screenshot to better visualise the phenomenon:

a

Hope this helps.

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  • $\begingroup$ Thank you for your clear explanation of what a colligative property is, though what I was looking for is whether more examples of colligative properties are there? $\endgroup$ – Pritt Balagopal Apr 11 '17 at 2:03
  • $\begingroup$ My bad, sorry I haven't realized that you explained the surface tension. Thanks! $\endgroup$ – Pritt Balagopal Apr 11 '17 at 8:04
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    $\begingroup$ That's okay, I had included a bit of explanation, so that even when you encounter other physical properties of substances, you'll easily understand to which category they belong. $\endgroup$ – xavier_fakerat Apr 11 '17 at 9:06

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