Which of the following statements is NOT correct about surface tension?
At room temperature, surface tension of water is less than ethyl alcohol.
The correct answer is the surface tension of water at room temperature is less than that of ethyl alcohol.
Key Points
- Surface tension is actually typically measured in dynes/cm, which indicates the force required to break a film of 1 cm length. Thus, option 1 is correct.
- Due to surface tension, the shape of a water droplet is spherical.Thus, option 2 is also correct.
- The spherical shape is a result of surface tension minimizing the surface area of the droplet, as a sphere is the shape that has the least surface area for a given volume.
- Contrary to statement 3, at room temperature, the surface tension of water is actually greater than that of ethyl alcohol. For example, at 20°C, the surface tension of water is 72.8 dynes/cm, while the surface tension of ethyl alcohol is 22.3 dynes/cm.
- The cohesive forces between liquid molecules are actually responsible for the phenomenon known as surface tension. These forces cause the liquid to behave as if it is covered by a stretched elastic sheet, a property known as surface tension. Thus, option 4 is also correct.
Important Questions from Surface Tension
Falling drops of rain break up and coalesce with each other and finally achieve an approximately spherical shape in the steady state. The radius of such a drop scales with the surface tension σ as
The property of a fluid which enables it to resist tensile stress is known as
Above the critical micelle concentration (CMC), the option which correctly describes the variation of molar conductivity with increase in concentration of sodium dodecylsulphate în aqueous solution is
If the surface tension of the soap bubble is 0.035 N/m, then the work done in blowing the soap bubble of radius 5 cm in the air is.
Addition of detergent to liquid
