Why does water have a concave meniscus and mercury a convex meniscus?

Why does water have a concave meniscus and mercury a convex meniscus?

A concave meniscus, which is what you normally will see, occurs when the molecules of the liquid are attracted to those of the container. This occurs with water and a glass tube. A convex meniscus occurs when the molecules have a stronger attraction to each other than to the container, as with mercury and glass.

Why does water show concave meniscus?

The force of attraction similar molecules is called cohesive force and that between dissimilar molecules is called adhesive forces. Ashesive forces act between water molecules and glass molecules. Due to stronger adhesive forces over cohesive forces, water shows concave meniscus in narrow glass tube.

Why mercury has its meniscus upward?

At sea level atmospheric pressure is greater than that of mountains , therefore boiling point of liquids is high. Q18) meniscus of water is concave(downward) but the meniscus of mercury is convex (upward) . Therefore mercury falls down from the sides attach to the wall and a concave or upward meniscus is obtained.

Why does water stick to glass but mercury does not?

The angle of contact between water and glass is whereas that between mercury and glass is obtuse. Hence cohesive force between molecules of mercury is more than the adhesive force between molecules of mercury and glass.

Why water in a narrow glass tube has a concave meniscus?

For water in a glass tube, the forces of adhesion between the water and glass molecules are greater than the force of cohesion between the water molecules hence water clings to glass forming a concave meniscus.

Why does the bottom of vessel filled with water appear to be concave when viewed from above?

This is due to the refraction. This is because as the light rays transition and pass through the air-water interface, they get bent due to refraction. The light rays are bent away from the normal making us perceive the bottom of the pond or tank as shallow or raised.

What is the difference between water and mercury?

Mercury is a very dense, heavy, silver-white metal that is a liquid at room temperature. Mercury has a density of 13.5 g/mL, which is about 13.5 times denser than water (1.0 g/mL), so a small amount of mercury like this feels unexpectedly heavy.

What kind of meniscus does mercury form?

convex
Water meniscus is convex, mercury menisucs is concave A concave meniscus, which is what you normally will see, occurs when the molecules of the liquid are attracted to those of the container.

What is upward meniscus?

What is Meniscus? The meniscus of a liquid is the upward or downward curve seen at the top of a liquid in a container. The nature of curve whether upward (convex) or downward (concave) depends on the surface tension the liquid and its adhesion capacity to the wall of the container.

What causes water to have a convex meniscus?

A concave meniscus, which is what you normally will see, occurs when the molecules of the liquid are attracted to those of the container. This occurs with water and a glass tube. A convex meniscus occurs when the molecules have a stronger attraction to each other than to the container, as with mercury and glass.

Why does Mercury have a concave meniscus?

This may be seen between mercury and glass in barometers and thermometers. Conversely, a concave meniscus occurs when the molecules of the liquid attract those of the container’s, causing the surface of the liquid to cave downwards.

When do you get concave and convex meniscus?

You can get a concave and convex meniscus. Convex ones are prdouced when molecules have a stronger attraction to each other than to the container. Concave meniscus’ are produced when molecules have a stonger attraction to the container.

What causes a glass tube to form an inverted meniscus?

The meniscus that forms in a glass tube is caused by water adhesion to the polar molecules in the glass. The plastic is chemically similar to oil so it tends to repel water thus it pushes away the water where it contacts the tube. This makes it form an inverted meniscus. There is a similar effect when you look at mercury in a glass tube.