In chemistry and in physics, the movement of particles becomes very important. One way in which particles move is through effusion. The formula for the rate of effusion of gas molecules was developed by a chemist by the name of Thomas Graham in the 19th century.
December 21, 1805�September 16, 1869.
Thomas Graham was born in December of 1805 in Glasgow, Scotland. His father was a workman who desired that his son enter the Church of Scotland. However, Graham became a student at the University of Glasgow in 1819, where he became interested in the field of chemistry. He left the university in 1826 and went off to be a professor of chemistry at several universities, two of which were the Royal College of Science and Technology and
…show more content…
His study in the field of colloids (a type of homogenous mixture) led to the discovery of dialysis and his earning of the name �the father of colloid chemistry.�
Another of Graham�s accomplishments was in his study of diffusion and effusion of gases. His formula for the effusion of gases even carries his name; it is called Graham�s Law.
Graham�s Law
�Physics. The flow of a gas through a small orifice at such a density that the mean distance between the molecules is large compared with the diameter of the orifice� (�effusion�).
In other words, effusion is the flow of individual gas molecules through a hole that is smaller than the mean free path, which is �the average distance [a] particle travels between collisions with other particles� (�Mean free path�). This means that in effusing through the hole the gas molecules do not collide with one another. ef�fu�sion �noun
One of the postulates of the Kinetic Molecular Theory states that average kinetic energy of gas particles depends solely on the temperature of the gas. Since this is the case, the kinetic energy of two gas molecules, hydrogen and oxygen for example, may be written as the
It started one day in a science classroom. That is where I learned about diffusion. Diffusion is the movement of a substance across a membrane, due to a difference in concentration, without any help from other molecules. (Unknown, 2) In the egg lab the egg experienced diffusion over the course of several days. During the lab I also learned about hypertonic solutions and hypotonic solutions. The hypertonic solutions concentration of the cell is less than the outside of the cell. (Trent, 1) Hypotonic solutions have a higher concentration in it than the area surrounding it. (Trent, 1) I learned about hypertonic solutions when we placed the egg in corn syrup which caused the egg to deform and become squished. I learned about hypotonic solutions when we placed the egg in water which caused the egg to swell. This process can also be defined as osmosis which is the diffusion of water molecules across a membrane. (Unknown, 2) When we first got the egg it would be an isotonic solution meaning that having equal tension (Unknown,1) which would mean that the same amount was inside the cell as outside of it. The purpose of the experiment was to learn about diffusion, concentration gradient, passive transport,
The side of the membrane that has the higher concentration is said to have the concentration gradient. It drives diffusion because substances always move down their concentration gradient. The pressure gradient also plays a role in diffusion. Where this is a pressure gradient there is motion of molecules. The pressure gradient is a difference in pressure between two different points.
After being educated at Trinity College Dublin he moved to Queens University in Dublin where he worked as the Secretary of the Administrative Headquarters of the Queens Colleges. It was then when he produced his most important conceptions and calculations. His particular theory was that electrical charges in atoms are comprised of negatives which he would call electrons. He calculated the magnitude of a particle of electricity, or Stoney Unit which he would later name the electron in one of his papers in the Transactions of the Royal Dublin Society in 1891. The path taken to get to Stoney Units utilized the Stoney Scale which was the mathematical equation he developed to get his desired answer when
Convection is a transfer of internal energy into or out of an object by the physical movement of a surrounding fluid that transfers the internal energy along with its mass. According to Oxford Dictionary, convection is the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder or denser material to sink under gravity's influence, that results in transfer of heat. Two fluids are liquid and gas.The fluid above a hot surface expands, becomes less dense, and rises.This applies to objects such as steam from a hot cup of coffee turning cool, ice melting like heat moving to ice from the air, or frozen material becoming raw like how frozen food thaws more quickly under cold running water. When
The Importance of Diffusion to Living Organisms Diffusion is basically the movement of chemical species (ions or molecules) under the influence of concentration difference. The species will move from the high concentration area to the low concentration area till the concentration is consistent in the whole system. Diffusion mostly occurs in gases and liquids as these can move freely. The main features of an efficient diffusion system would be that it has a large surface area, thin membrane and a continuous supply of substances. A large surface area is needed so that high amount of substances can be exchanged at a time while the thin membrane means that the diffusion pathway would be short so that it is more efficient.
Benjamin Franklin was born in Boston in 1706 into a family of ten children and to a soap and candle maker. Although Ben had some formal education, he was primarily self-taught. At the age of ten, he served an apprenticeship for his father before going on to serve as an apprentice for the New England Courant. This is where he first published his works. (DOSB,129)
5. In a gas increasing the pressure means molecules are more squashed up together, so there will be more collisions. My Investigation. I am going to investigate the concentration variable. I have chosen this because in my opinion it will be the easiest one to measure.
The purpose of this lab was to see firsthand the diffusion of a substance across a selectively permeable membrane. Diffusion is the movement of molecules from an area of high concentration to an area of lower concentration until both concentrations are equal, or as you could more professionally call it, equilibrium. This concept is one that we have been studying in depth currently in Biology class.
Bruce Mattson. “Henry Cavendish 1731-1810”. History of Gas Chemistry. Updated September 25, 2001. Retrieved December 1, 2011
At a higher temperature there will be more particles colliding with enough energy to make the reaction happen. This initial energy is known as the activation energy, and it is needed to break the initial. bonds. The..
Lord Kelvin, or William Thomson, was destined for greatness at birth. He was born June 26, 1824 in Belfast, Ireland. His father was a prestigious mathematics professor at Glasgow University and his brother later became a professor of engineering (Webster 2). Both William Thomson and his older brother, James, were homeschooled by their father, also named James Thomson, in their early years. Their father encouraged them to discover and pursue all academic possibilities.
Boyle's law states that the volume of gas varies indefinitely with the pressure applied to it.
The foundations of fluid mechanics really crystallized in the 18th century. One of the more famous scientists, Daniel Bernoulli (1700–1782, Dutch-Swiss), point...
The rate of reaction is how quickly or slowly reactants in chemical reactants turn into products. A low reaction rate is when the reaction takes a long time to take place; hence, a reaction that occurs quickly has a high reaction rate. A rate refers to how slow or quick the product is produced. It is possible to control the rate of chemical reactions and speed up or slow down the rate of chemical reactions by altering three main factors which are temperature, concentration and the surface area. When the temperature of the reactants increases, the molecules vibrate at a more intense speed therefore colliding with each other more frequently and with increased energy resulting in a greater rate of reaction. Accordingly, as the temperature decreases the molecules will move slower, colliding less frequently and with decreased energy resulting in the rate of reaction decreasing. Concentration is how much solute is dissolved into a solution and is also a factor that affects the rate of reaction. When the concentration is greater this means there is an increased amount of reactant atoms and molecules resulting in a higher chance that collisions between molecules will occur. A higher collision rate means a higher reaction rate. Consequently at lower concentrations there are reduced chances of the molecules colliding resulting in a lower reaction rate. The measurement of how much an area of a solid is exposed is called the surface area. The quicker a reaction will occur the more finely divided the solid is. For example, a powdered solid will usually have a greater rate of reaction in comparison to a solid lump that contains the same mass for it has a lower surface area than the powdered solid.