The surface tension of mercury at normal temperature compared to that ...
Mercury is so heavy than water, so it needs higher surface tension to maintain a spherical shape of its drop.
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The surface tension of mercury at normal temperature compared to that ...
Surface Tension of Mercury vs Water
Introduction:
Surface tension is the property of a liquid due to which it tends to minimize its surface area and form spherical shapes. It is due to the cohesive forces between the molecules of the liquid.
Comparison of Surface Tension:
The surface tension of mercury is more than that of water at normal temperature. The surface tension of water at 20°C is 72.8 mN/m, whereas the surface tension of mercury at 20°C is 485 mN/m. The surface tension of mercury is much higher than that of water due to the stronger cohesive forces between the molecules of mercury.
Reasons for Higher Surface Tension of Mercury:
The higher surface tension of mercury is due to the following reasons:
- Mercury is a heavy metal with a high atomic number, which results in stronger interatomic forces.
- The atomic radius of mercury is smaller than that of water, which leads to a higher density of molecules in a given volume.
- The electrons in the valence shell of mercury are more tightly bound, resulting in stronger intermolecular forces.
Applications:
The high surface tension of mercury makes it useful in many applications, such as:
- As a working fluid in thermometers due to its high boiling point and low freezing point.
- In barometers, where the height of the mercury column is used to measure atmospheric pressure.
- In liquid mirror telescopes, where the surface tension of the mercury is used to create a smooth, reflective surface.
Conclusion:
In conclusion, the surface tension of mercury is more than that of water at normal temperature due to the stronger intermolecular forces between the molecules of mercury.
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