Avogadro, Amedeo hypothesis, 78 number

Mendeleev also attended the 1860 Karlsruhe Congress, the first international chemistry conference. Many of the leading chemists of the day were in attendance, and one of the central questions addressed was the appropriate method for calculating atomic weight. Different chemists used different systems, leading to widespread confusion over everything from nomenclature to chemical formulas. Mendeleev heard the Itafian chemist Stanislao Cannizzaro present Amedeo Avogadro s hypothesis that equal vol-tunes of gas under equal temperature and pressure contained equal numbers of molecules. 

The first to point out the necessity of this assumption that, in gases, equal numbers of particles take up equal volumes, was the Italian chemist Amedeo Avogadro (1776-1856). The assumption, advanced in 1811, is therefore known as Avogadro s hypothesis. 

Three years later Amedeo Avogadro interpreted Gay-Lussac s observation by proposing what is now known as Avogadro s hypothesis Equal volumes of gases at the same temperature and pressure contain equal numbers of molecules. For example, 22.4 L of any gas at 0 °C and 1 atm contain 6.02 X 10 gas molecules (that is, 1 mol), as depicted inT FIGURE 10.10. 

Avogadro s law (Avogadro s hypothesis) The principle that equal volumes of all gases at the same temperature and pressure contain equal numbers of molecules. It is often called Avogadro s hypothesis because it was first proposed by the Italian chemist and physicist Amedeo Avogadro (1776-1856) in 1811. It is strictly true only for ideal gases. 

Such a simple empirical law as this called for a simple theoretical interpretation, and in 1811 Amedeo Avogadro (1776-1856), professor of physics in the University of Turin, proposed a hypothesis to explain the law. Avogadro s hypothesis was that equal numbers of molecules are contained in equal volumes of all dilute gases under the same conditions. This hypothesis has been thoroughly verified to within the accuracy of approximation of real gases to ideal behavior, and it is now called a law— Avogadro s law. ... 

While most beginning chemistry students associate the name of Avogadro with moles and Avogadro s number, Amedeo Avogadro s principal contribution to the chemical sciences is the hypothesis that, at equal temperatures and pressures, equal volumes of gas contain equal numbers of particles. This work made the determination of several atomic and molecular masses possible. In other words, the volume of a gas is directly proportional to the number of gas molecules, as long as temperature and pressure are held constant. 

Amedeo Avogadro developed the hypothesis that equal volumes of different gases contain an equal number of molecules, if the gases are at the same temperature and pressure. The proportionality between volume and number of moles is called Avagadro s Law, and the number of molecules in a mole is called Avagadro s Number. Both were posthumously named in his honor. 

In 1800, chemists did not know that the elementary gases were diatomic, and they wondered how two molecules of HCl were formed from one molecule of H and one of Cl. The law of combining volumes led Amedeo Avogadro (1776-1856) to postulate in 1811 a hypothesis that equal volumes of gases under like conditions of temperature and pressure contain equal numbers of molecules. The fact that molecules of hydrogen and chlorine had to be diatomic stemmed from this generalization. 

The work of the Itahan scientist Amedeo Avogadro complemented the studies of Boyle, Charles, and Gay-Lussac. In 1811 he published a hypothesis stating that at the same temperature and pressure, equal volumes of different gases contain the same number of molecules (or atoms if the gas is monatomic). It follows that the volume of any given gas must be proportional to the number of moles of molecules present that is. 

In 1811, Amedeo Avogadro" (in full, Lorenzo Romano Amedeo Carlo Avo-gadro di Quaregua e di Cerreto, 1776-1856) used Gay-Lussac s, Dalton s, and others works to make his hypothesis equal volumes of gases (at same temperature and pressure) have equal numbers of molecules. Interestingly, this contribution was largely forgotten until resurrected by Cannizaro in 1858. ... 

Amedeo Avogadro (1776-1856) was an Italian physicist who made many early contributions to the concepts of molecular behaviour and relative molecular mass (formerly known as molecular weight) (Figure 1.48). His most critical contribution was making the distinction between atoms and molecules. His hypothesis was based on the careful experimental work by Gay-Lussac and John Dalton s atomic theory. He trained and practised as a lawyer, but later became Professor of Physics at Turin University. As a tribute to him, the number of particles in one mole of a substance is known as the Avogadro constant (formerly known as the Avogadro number). 

Amedeo Carlo Avogadro (1776-1856) was an Italian chemist, most noted for his contributions to the theory of molarity and molecular weight. In 1811, he declared the hypothesis of what we now call Avogadro s law Equal volumes of gases, at the same temperature and pressure, contain the same number of molecules. Hence, the gas laws of Boyle, Mariotte and Cay-Lussac in combination with Avogadro s Law can be generalized by the ideal gas law. The Avogadro constant Na, that is, the number of molecules in one mol is 6.022 x 10 mol is named in his honor. The numerical value of /Va was first estimated in 1865 by Johann Josef Loschmidt (1821-1895), an Austrian scientist. 

In 1811 Amedeo Avogadro (1776-1856) announced his hypothesis that under conditions of the same temperature and pressure, equal volumes of all gases contained equal number of molecules. This hypothesis greatly helped in... 

Amedeo Avogadro (1776-1856) was an Italian physicist. His famous hypothesis about gases was that at the same pressures and temperatures, equal volumes of gases contain equal numbers of particles. Chemists and physicists in Avogadro s time were still undecided about the existence of atoms and molecules. Without experimental evidence to support his hypothesis, Avogadro was pretty much ignored during his lifetime. 

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