the magnitude of surface tension of liquid dpends on the attractive forces between the molecules. Arrange the following in increasing order of surface tension :
Water, alcohol `(C_(2)H_(5)OH)` and hexane `[CH_(3)(CH_(2))_(4)CH_(3)")"]`.

Explanation

In the above given molecules, only hexane `(CH_(3)(CH_(2))_(4) CH_(3))` is a non-polar molecule in which only London dispersion forces exist. These forces are very weak while both water and alcohol are polar molecules in which dipole-dipole interactions as well as H-bonding exists.
However, H-bonding interactions are much stronger in water than `H_(2)O`, therefore, it possesses stronger intermolecules than alcohol and hexane. Hence, the increasing order of surface tension is
hexane `lt` alcohol `lt` water
Greater is the attractive forces between the molecules, greater is the magnitude of surface tension of liquid.