Give two examples of diffusion which disappear from solid to gaseous state
Answers
Answer:
Diffusion is a physical process that refers to the net movement of molecules from a region of high concentration to one of lower concentration. The material that diffuses could be a solid, liquid or gas. Similarly, the medium in which diffusion occurs could also be in one of the three physical states.
One of the main characteristics of diffusion is the movement of molecules along the concentration gradient. While this could be facilitated by other molecules, it does not directly involve high-energy molecules such as adenosine triphosphate (ATP) or guanosine triphosphate (GTP).
The rate of diffusion depends on the nature of interaction between the medium and material. For instance, a gas diffuses very quickly in another gas. An example of this is the way the noxious smell of ammonia gas spreads in air. Similarly, if a canister of liquid nitrogen leaks a little, nitrogen gas that escapes would quickly diffuse into the atmosphere. The same gas would diffuse slightly more slowly in a liquid such as water and slowest in a solid.
Similarly, two miscible liquids will also diffuse into each other to form a uniform solution. For instance, when water is mixed with glycerol, over time the two liquids diffuse radially into each other. This can even be observed visually by the addition of different colored dyes to each of the liquids. However, the same phenomenon is not seen when immiscible liquids like petrol and water are mixed together. Diffusion happens slowly and only across the small surface of interaction between the two fluids.
Examples of Diffusion
Diffusion is an important part of many biological and chemical processes. In biological systems, diffusion occurs at every moment, across membranes in every cell as well as through the body.
For example, oxygen is at a higher concentration inside arteries and arterioles, when compared with the oxygen levels in actively respiring cells. By the time blood flows into capillaries in the muscle or liver, for instance, there is only a single layer of cells separating this oxygen from hepatocytes or skeletal muscle fibers. Through a process of passive diffusion, without the active involvement of any other molecule oxygen passes through the capillary membrane and enters cells.
Cells utilize oxygen in the mitochondria for aerobic respiration, which generates carbon dioxide gas as a byproduct. Once again, as the concentration of this gas increases within the cell, it diffuses outwards towards capillaries where the force of flowing blood removes the excess gas from the tissue region. This way, the capillaries remain at a low carbon dioxide concentration, allowing the constant movement of the molecule away from cells.
This example also shows that the diffusion of any one material is independent of the diffusion of any other substances. When oxygen is moving towards tissues from capillaries, carbon dioxide is entering the bloodstream.
Factors that Affect Diffusion
Diffusion is affected by temperature, area of interaction, steepness of the concentration gradient and particle size. Each of these factors, independently and collectively can alter the rate and extent of diffusion.
molecules in the periphery, rapidly moving molecules in the air also influence their movement, allowing them to diffuse into the air. This creates a concentration gradient, with concentration of carbon dioxide gradually decreasing with distance from the lump of dry ice.
With increase in temperature, the kinetic energy of all particles in the system increases. This increases the rate at which solute and solvent molecules move, and increases collisions. This means that the dry ice (or even regular ice) will evaporate faster on a warmer day, simply because each molecule is moving with greater energy and is more likely to quickly escape the confines of a solid state.
Explanation:
Diffusion is a physical process that refers to the net movement of molecules from a region of high concentration to one of lower concentration. The material that diffuses could be a solid, liquid or gas. Similarly, the medium in which diffusion occurs could also be in one of the three physical states.
One of the main characteristics of diffusion is the movement of molecules along the concentration gradient. While this could be facilitated by other molecules, it does not directly involve high-energy molecules such as adenosine triphosphate (ATP) or guanosine triphosphate (GTP).