Why does water form a meniscus in a narrow container?
Water molecules are attracted to the molecules in the wall of the glass beaker. And since water molecules like to stick together, when the molecules touching the glass cling to it, other water molecules cling to the molecules touching the glass, forming the meniscus.
What type of meniscus does water have?
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 a meniscus and why is it important for measuring liquids?
A meniscus occurs because of surface tension in the liquid and must be read at eye level. For a concave meniscus, the correct volume will be read at the bottom of the curve. For a convex meniscus, the opposite is true and the correct reading will be at the top of the curve.
How should the meniscus be read when measuring the volume of a liquid in a small diameter container?
The key to getting an accurate reading, is to measure the center of the meniscus whether it be concave or convex. E.g. with a concave meniscus, measure the bottom of the meniscus and for convex meniscus, take the reading from the top of the meniscus.
What is a meniscus and why does it form?
Fluid molecules are attracted to the molecules in the wall of the glass beaker and since fluid molecules like to stick together, when the molecules touching the fluid cling to it, other molecules of fluid cling to the molecules touching the glass, which forms a meniscus.
What causes a meniscus?
A torn meniscus can result from any activity that causes you to forcefully twist or rotate your knee, such as aggressive pivoting or sudden stops and turns. Even kneeling, deep squatting or lifting something heavy can sometimes lead to a torn meniscus.
What determines the meniscus shape?
Answer. When liquid water is confined in a tube, its surface (meniscus) has a concave shape because water wets the surface and creeps up the side. 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.
Why meniscus of water is concave but that of mercury is convex?
Solution : 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. However, in mercury, th cohesive force are stronger than the adhesive forces. As a result, its meniscus is convex.
What is the meniscus and how should it be used when measuring the volume of water in a graduated cylinder?
A meniscus is the curvature of the surface of the water. Water “sticks” to the walls of the graduated cylinder, but only on the sides and not the middle. When students look at the surface, the water level is not straight. Measurement should be at the lowest point (see figure to the right).
What is meniscus and why does it occur?
A concave meniscus occurs when the particles of the liquid are more strongly attracted to the container (adhesion) than to each other (cohesion), causing the liquid to climb the walls of the container. This occurs between water and glass.
How do you read a meniscus on different liquids?
The long answer: To read a meniscus, you first need to see what type of meniscus your liquid forms. If the meniscus is a concave meniscus, read at the lowest level of the curve. If the meniscus is convex, take your measurement at the highest point of the curve.
What is a meniscus used for in chemistry?
A concave surface of a liquid resulting from surface tension. The bottom of the meniscus is used to measure the volume of a liquid in apparatus such as a graduated cylinder.
What does the meniscus do?
The meniscus is a C-shaped piece of tough, rubbery cartilage that acts as a shock absorber between the shinbone and the thighbone. It can be torn if you suddenly twist your knee while bearing weight on it.
Whats is a meniscus?
The meniscus is a c-shaped pad of cartilage in the knee that acts as a shock absorber. Each knee has two menisci. Meniscus tears are common knee injuries.
Why is the shape of meniscus is different in different liquids?
This phenomenon is due to the surface tension of the liquid. Or we can also say that this is due to the difference between the forces of attraction (adhesive forces) between the inner surface of the tube and the liquid molecules and the force of attraction (cohesive forces) between the liquid molecules.
How does it depend on the shape of liquid meniscus in a tube?
Answer: The angle made by the tangent drawn to the meniscus from the point of contact with the walls of the container measured from within the liquid is called the angle of contact. It depends on the atmospheric pressure, adhesive and cohesive forces of the liquid in the tube.
Why does water in a narrow glass tube have a concave meniscus while mercury in the same tube has a convex meniscus?
When liquid water is confined in a tube, its surface (meniscus) has a concave shape because water wets the surface and creeps up the side. Mercury does not wet glass – the cohesive forces within the drops are stronger than the adhesive forces between the drops and glass.
What part of the meniscus must be used to find the volume of water?
For water and most liquids, this is the bottom of the meniscus. For mercury, take the measurement from the top of the meniscus.