Describe the relationship between tube diameter and capillary action

Capillary action, factors affecting, its applications and everyday examples

describe the relationship between tube diameter and capillary action

Capillary action (or capillarity) describes the ability of a liquid to flow against These two, together with the contact area (the tube's diameter). Capillary action seen as water climbs to different levels in glass tubes of different diameters. Credit: Dr. Clay Robinson, PhD, West Texas A&M. Balancing the surface tension force and pressure force for the liquid that rises in As you can see, height is inversely proportional to the radius of tube. of flow of water through a capillary tube if the diameter of the tube is tripled? What is the relation between surface tension and the height of liquid in a.

Hence, knowledge of the liquid is not sufficient to determine when capillary action will occur, since we must also know the chemical composition of the tube. These two, together with the contact area the tube's diametercomprise the key variables. In contrast, mercury is characterized by stronger cohesion, and hence its capillarity is much lower.

describe the relationship between tube diameter and capillary action

The height h of a liquid inside a tube is given by the formula So what's going on here? In case the forces of adhesion are greater than those of cohesion and gravity when it existsthe molecules of the liquid cling to the wall of the tube.

We will observe that the upper surface of the liquid becomes concave the height of the liquid at the contact area is higher than its height at the center of the tube. The cohesive forces between the molecules of the liquid are "attempting" to reduce the surface tension i. In doing so, the molecules keep climbing up until a steady state between cohesion and adhesion is achieved with or without the gravity component.

This also explains why this phenomenon occurs exclusively in thin tubes also in the absence of gravity.

What is capillary action and how is it affected by gravity? Ariel & Michal

In wider vessels, only a small fraction of the liquid comes into contact with the vessel walls, and so adhesive forces are negligible and there is hardly any rising of the liquid. Soil water rises to the surface by capillary action and evaporates. To conserve soil water, the farmers plough their fields in summer. The loosening of the top layer of the soil breaks up the fine capillaries through which the deeper down water is sucked up.

Thus the loss of water in the soil is prevented. Due to depression in the level of mercury in a capillary tube, a correction is to be applied for mercury barometer. Capillary Action in Water: In case of the capillary tube, its bore is very small hence all the points on the free surface are very close to the walls, and hence, the entire free surface becomes curved. It is called a meniscus. In the case of a glass capillary immersed in water, the meniscus is concave upwards. The air pressure on the upper or concave side of the meniscus is the atmospheric pressure P.

Capillary action and why we see a meniscus - Chemistry - Khan Academy

We know that the pressure on the convex side of the free surface is less than that on the concave side. It means that the pressure just below the meniscus i. The pressure at points just below the flat surface of the water in the surrounding vessel is atmospheric pressure.

The system is, therefore not in equilibrium and the liquid rises in the capillary tube till the equilibrium is reached. Capillary Action in case of Mercury: In case of a capillary tube, its bore is very small hence all the points on the free surface are very close to the walls, and hence, the entire free surface becomes curved. In the case of glass capillary immersed in mercury, the meniscus is convex upwards.

Capillary Action - Chemistry LibreTexts

The air pressure on the upper or convex side of the meniscus is the atmospheric pressure P. We know that the pressure on the concave side of the free surface is greater than that on the convex side.

describe the relationship between tube diameter and capillary action

The pressure of points just below the flat surface of the mercury in the surrounding vessel is atmospheric pressure. If a glass tube of a smaller bore capillary tube is immersed in a liquid which wets the glass waterthen the liquid level inside the tube rises.

If the tube is immersed in a liquid which does not wet the glass mercurythen the liquid level inside the tube decreases. Consider a capillary tube immersed in a liquid that wets it. The liquid will rise in the capillary tube.

What is capillary action and how is it affected by gravity? Ariel & Michal

The surface of the liquid will be concave. This explains the rise in the liquid layer in the capillary tube. Due to this force the liquid rise up in the tube.

The weight of liquid acts vertically downward. The liquid goes on rising till the force of surface tension is balanced by the weight of the liquid column. The height to which the liquid rises in the capillary tube is inversely proportional to the radius of the bore of the capillary tube.