Is a meniscus concave or convex?

Is a meniscus concave or convex?

A meniscus is a phase boundary that has been curved because of surface tension. In the case of water and most liquids, the meniscus is concave. Mercury produces a convex meniscus.

Do all liquids have concave meniscus?

All liquids have concave meniscus. Hint: Convex meniscus is formed when the cohesive forces are stronger , that is , attractive forces between molecules of same substance whereas concave meniscus is formed when the adhesive forces are stronger , that is , attraction between molecules of different substance.

What will be the shape of liquid meniscus?

In simple words the attractive forces between particles of the liquid is greater. Due to these cohesive forces the liquid meniscus forms a convex shape.

What is convex meniscus?

A convex meniscus occurs when the molecules have a stronger attraction to each other than to the container, as with mercury and glass. A flat meniscus occurs with water in some types of plastic tubes; tubes made out of material that water does not stick to.

Is water concave or convex?

In case of water, the adhesive forces in the molecules of glass and water are stronger than the cohesive forces in the water molecules. Therefore, the meniscus of water is concave.

What is concave 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.

What is lower meniscus and upper meniscus?

Reading a Meniscus You may notice a ‘line’ of liquid at the very top, forming the curve itself. The bottom of the curve is the lower side of this line. For a convex meniscus, you do the opposite and read the volume at the top of the curve.

Why does mercury form a convex meniscus?

Formation of a Meniscus 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.

What causes a meniscus to be concave or convex?

The meniscus can be either concave or convex, depending on the surface tension of the liquid and its adhesion to the wall of the container. A concave meniscus occurs when the molecules of the liquid are more strongly attracted to the container than to each other. The liquid appears to “stick” to the edge of the container.

Why does a meniscus appear on a liquid?

This is the downward or upward curve at the surface of a liquid in a container. Depending on how the molecules of the liquid interact, this curve may either be concave or convex. A meniscus occurs because of surface tension in the liquid and must be read at eye level.

Can you read a meniscus from the bottom?

In the biology lab, we’re probably not working with oil or milk, but we do work with other liquids, and measuring them correctly is just as important here as in the kitchen. Luckily, reading a meniscus is easy if you know how. For a concave meniscus, the volume of the liquid in the container is read from the bottom of the curve.

How are Convex menisci used in surface science?

Convex menisci occur, for example, between mercury and glass in barometers and thermometers. Tensiometers measure liquid surface tension based on liquid menisci. The formation of menisci is commonly used in surface science to measure contact angles and surface tension.