The table shows the values of surface tension
for 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.