Chemical Engineering - Fluid Mechanics - Discussion
Discussion Forum : Fluid Mechanics - Section 1 (Q.No. 1)
1.
The fluid property, due to which, mercury does not wet the glass is
Discussion:
45 comments Page 3 of 5.
Mohit said:
6 years ago
The reason is cohesion. Due to cohesive force between the molecules of mercury droplet it shows high surface tension and which is also the cause of capillary fall in capillary tube. Higher the cohesiveness lesser the tendency to wet the surface.
Mukesh said:
6 years ago
It's cohesion.
Vishaka said:
7 years ago
Cohesion is the correct answer. Because cohesion means cohesion meansCLES OF SAME SUBSTANCE. And Mercury has more cohesive property.
Shiv said:
1 decade ago
Actually, both answer (surface tension, cohesive) are correct because surface tension is caused by cohesive force b/w surface molecules.
Jyoti said:
1 decade ago
Hello Sachin !
surface tension of any fluid particle acts radially over the tangential components so that the fluid particles try to obtain a minimal surface area. In this stake the mercury droplet gets spherical and thus have minimum contact just at only one point on the glass
surface tension of any fluid particle acts radially over the tangential components so that the fluid particles try to obtain a minimal surface area. In this stake the mercury droplet gets spherical and thus have minimum contact just at only one point on the glass
Ashish jha said:
1 decade ago
It should be force of adhesion, because force of adhesion works between two different surfaces.
Archana said:
1 decade ago
The reason we consider the surface area of the entire mass of mercury, including the part of the surface that is in contact with the glass, is because mercury does not adhere at all to glass. So the surface tension of the mercury acts over its entire surface area, including where it is in contact with the glass. If instead of glass, the tube were made out of copper, the situation would be very different.
Shaheer Hassan said:
1 decade ago
The reason should be the force of cohesion. It is because adhesion is the property by which things gets wet after having a contact with the liquid while surface tension makes the surface intact. Cohesion is the force responsible for surface tension and therefore it restricts the liquid from adhering with the other surfaces. Cohesion is the force among the molecules of the same matter.
Deepika.M said:
1 decade ago
It is the cohesion force that predominates in mercury and hence the molecules of mercury tend to remain together as cohesion is attractive force between like particles. Hence the glass surface doesn't get wet.
Anwesa said:
1 decade ago
Mercury does not wet glass - the cohesive forces within the drops are stronger than the adhesive forces between the drops and glass. When liquid mercury is confined in a tube, its surface (meniscus) has a convex shape because the cohesive forces in liquid mercury tend to draw it into a drop.
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