The Avogadro constant is named after the early nineteenth century Italian scientist Amedeo Avogadro, who is credited (1811) with being the first to realize that the volume of a gas (strictly, of an ideal gas) is proportional to the number of atoms or molecules. The French chemist Jean Baptiste Perrin in 1909 proposed naming the constant in honor of Avogadro. American chemistry textbooks picked it up in the 1930's followed by high school textbooks starting in the 1950s.
The unit "mole" was introduced into chemistry around 1900 by Ostwald, and he originally defined this unit in terms of gram. Gram is a unit of mass; but what is the mole a unit of? Ostwald did not say;3 however, several years later, he did make it clear that the concept of mole should be linked to the ideal gas. 4
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. . das in Grammen augedruckte [. . .] Molekulargewicht eines Stoffes soll fortan ein Mol heissen]" Ref. 7).
4 "That amount of any gas that occupies a volume of 22414 mL in normal conditions is called one mole [eine solche Menge irgendeines Gases, welche das Volum von 22412 ccm im Normalzustand einnimt nennt man ein Mol]"
middle of paper ... ... The Web. 22 Feb. 2014. http://www.chemheritage.org/discover/online-resources/chemistry-in-history>.
Although the atomic theory was developed in increments, George Johnston Stoney is most famous for contributing the term electron: fundamental unit quantity of electricity. Stoney would develop the concept fourteen years before he coined the term electron. He also made contributions to the theory of gasses, cosmic physics, and estimated the number of molecules in a cubic millimeter of gas.
On earth, substances tend to exist in one of three phases; either a solid, liquid, or gas. While solids and liquids have defining factors such as volume, and for solids only, a shape, gases exhibit neither of these. Gases naturally take the shape of and expand into the volume of the container, and change when placed in different surroundings. As gases are constantly moving around and colliding with the walls, they exert a force, or pressure, on the walls of its container. Pressure is one of the characteristic behaviors that gases exhibit, but due to their nature, various factor effect the pressures that a gas can exert. Towards the end of the eighteenth century, scientist began to stumble upon these various factors that affect gases, especially
The Equation Of State These three gas laws that were proposed by Boyle, Amontons and Charles can be summarised as follows: For a fixed mass of gas pV = constant if T = constant (i) p/T = constant if V = constant (ii) V/T = constant if p = constant (iii)
... is not the only thing it taught the community of chemists though, it also showed that reactions are able to sit at equilibrium for a while before fully going to completion. After the academy had seen the work he had done in with the reaction, he became a director of the Second Chemical Institute of the Berlin University. He worked here from 1891 to 1905. During this time he also proved the law of concentration of mass and energy to be true, adding to his contributions the science of chemistry. He died in 1910. (3)
Michael Guillen, the author of Five Equations that Changed the World, choose five famous mathematician to describe. Each of these mathematicians came up with a significant formula that deals with Physics. One could argue that others could be added to the list but there is no question that these are certainly all contenders for the top five. The book is divided into five sections, one for each of the mathematicians. Each section then has five parts, the prologue, the Veni, the Vidi, the Vici, and the epilogue. The Veni talks about the scientists as a person and their personal life. The Vidi talks about the history of the subject that the scientist talks about. The Vici talks about how the mathematician came up with their most famous formula.
John Dalton John Dalton, born 6th September 1766, is known for developing the theory of the elements and compounds, atomic mass and weights and his research in colour blindness. He was born in Eaglesfield, Cumberland (now known as Cumbria). In school he was so successful that at the age of 12 he became a teacher. In 1785 he became one of the principles and in 1787 he made a journal that was later made into a book, describing his thoughts on mixtures of gases and how each gas acted independently and the mixtures pressure (which is the same as the gases volume if it had one). Therefore, the law of partial pressure was made.
In the early 1800’s, a scientist by the name of John Dalton developed a theory which we now refer to as Dalton’s law of partial pressure. John Dalton developed this law by experimenting with the gases in the atmosphere. “Dalton's experiments on gases led to his discovery that the total pressure of a mixture of gases amounted to the sum of the partial pressures that each individual gas exerted while occupying the same space”(A+E Networks, 2013). Mathematically, Dalton explained this law by stating, Ptotal= P1+P2+P3……Pn. These preliminary experiments that Dalton performed were based on the original 760 torr or 760 mmHg that had been earlier discovered by Torricelli. Dalton then realized that the 760 mmHg in the atmosphere is made up of gases such as oxygen, nitrogen, carbon dioxide, and a few other trace gases. The pressure given off by each of these gases is considered to be the partial pressure of the total atmospheric pressure. The percentages of these gases in the atmosphere at sea level are nitrogen 78.08%, oxygen 20.95%, carbon dioxide 0.03 %, and remaining trace gases 0.94% which make up a total of 100% in the atmosphere.
Le Chateliers discoveries were and are still essential to understanding key principles in chemistry. He invented instruments and tools to measure high temperatures and his studies in the areas explosive materials made it safer for minors to work. He his most remembered for his own principle dealing with equilibrium. In essence this principle says a reaction in an equilibrium state will compensate for changes in the system by counteracting the change to restore equilibrium. It helps chemists predict how changing the concentration, pressure, volume or temperature will affect their reactions. Le Chatelier’s work is impressive and he should always be remembered as one of the greatest chemists who has ever lived.
In 1916, Robert Millikan confirmed Einstein’s equation for the kinetic energy of the electron and Planck’s constant.
In April 1905 Einstein submitted his doctoral thesis "A New Determination of Molecular Dimensions" to the university in Zurich which was accepted in July. During this same year he published five pioneering papers...
Moles Volume HCl Volume Water 2 M 10 cm 3 0 cm 3 1.5 M 7.5 cm 3 2.5 cm 3 1 M 5 cm 3 5 cm 3 0.5 M 2.5 cm 3 7.5 cm 3
the bulk to ordinary matter; the volume of an atom is nearly all occupied by the
Gases are also very low in density. The average gas is 1000 times less than that of the average liquid. The volume of gas varies with many things including temperature and pressure. These are explained in Charles's and Boyle's laws.
remaining 20 percent is due to other gasses that are present in very small amounts? (Murck,