Discussin of Surface Tension

The table shows the values of surface tensionfor various liquids at certain temperature. The lowest values ofoccur for the noble gases neon and helium – for which intermolecular forces are very weak.

Liquid in Contact With Air

Temperature (Degrees Celsius)

Surface Tension ()

Benzene

20

28.9

Carbon Tetrachloride

20

26.8

Ethanol

20

22.3

Glycerin

20

63.1

Mercury

20

465

Olive Oil

20

32

Soap Solution

20

25

Water

0

75.6

Water

20

72.8

Water

60

66.2

Water

100

58.9

Oxygen

-193

15.7

Neon

-247

5.15

Helium

-269

0.12

Surface tension usually decreases as the temperature increases, because as the temperature increases, molecules become more widely separated and the intermolecular forces decrease.

Surface tension can be changed by mixing solutions. For instance the surface tension of water can be lowered by mixing it with soap. This also makes your clothes cleaner, because lowering the surface tension makes it easier for water to penetrate into the fibres and dissolve the dirt there.