Avogadro’s law Equal volumes of gases at the

Avogadro s law equal volumes of gases at the same temperature and pressure that contain the same number of molecules. 

Avogadro s law equal volumes of gases at the same temperature and pressure contain the same number of particles. (5.2) Avogadro s number the number of atoms in exactly 12 grams of pure 12C, equal to 6.022 X 1023. (3.2)... 

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, Avogadro postulated what is now known as Avogadro s law Equal volumes of gases, at equal temperatures and pressures, contain the same number of molecules. You will learn more about Avogadro s law in Unit 4. 

For a fixed quantity of gas at constant pressure, the volume is directly proportional to its absolute temperature (Charles s law). Equal volumes of gases at the same temperature and pressure contain equal numbers of molecules (Avogadro hypothesis). For a gas at constant temperature and pressure, the volume of the gas is directly proportional to the number of moles of gas (Avogadro s law). Each of these gas laws is a special case of the ideal-gas equation. 

The amount-volume relationships of ideal gases are described by Avogadro s law Equal volumes of gases contain equal numbers of molecules (at the same T and P). 

The pressure-volume relationships of ideal gases are governed by Boyle s law Volume is inversely proportional to pressure (at constant T and ri). The temperature-volume relationships of ideal gases are described by Charles s and Gay-Lussac s law Volume is directly proportional to temperature (at constant P and n). Absolute zero (-273.15°C) is the lowest theoretically attainable temperature. On the Kelvin temperature scale, 0 K is absolute zero. In all gas law calculations, temperature must be expressed in kelvins. The amount-volume relationships of ideal gases are described by Avogadro s law Equal volumes of gases contain equal numbers of molecules (at the same T and P). 

Avogadro s Law. Equal volumes of different gases at the same pressure and temperature contain the same number of molecules. From ihe concept of Ihe mole, a pound-mole of any subslance contains a mass equal in pounds to the molecular weight of the subslance, Thus the ratio of mole weigh lo molecular weight is a constant, and a mole or a chemically pure substance contains ihe same number of molecules, no matter what the subslance may be. Since a mole of any ideal gas occupies the same volume at a given pressure and temperature (ideal gas law), il follows that equal volumes of different gases at the same pressure and temperature contain the same number of molecules. 

In 1811, Avogadro formulated what is now known as Avogadro s hypothesis, which states that equal volumes of gases at the same temperature and pressure will contain equal numbers of molecules. It has been experimentally determined that 22.4 liters of any gas at 0 °C and 1 atm (standard temperature and pressure, STP) contain 1 mole of molecules (6.02 x lO ). This hypothesis allows for the statement of Avogadro s Law, which says that the volume of a gas, kept at constant pressure and temperature, is directly proportional to the number of moles of the gas. As a formula, this reads... 

Avogadro was the first to interpret the law of combining volumes in terms of interacting particles. He reasoned that the volume of a gas at a given temperature and pressure must depend on the number of gas particles. Avogadro s principle states that equal volumes of gases at the same temperature and pressure contain equal numbers of particles. 

In Chap. 4 we introduced the concept of the mole, the mass of a substance which contains the same number of fundamental units as a mole of any other substance. The original statement of that idea is called Avogadro s law, and applied to gases in which the fundamental units are molecules, it states Equal volumes of gases at the same pressure and temperature have the same number of molecules or moles, designated n. This adds a third gas law to the previous two ... 

Avogadro s law states that equal volumes of gases (at the same pressure and temperature) contain the same number of molecules. Therefore, If (within experimental error) equal volumes of H2 and CI2 react together, producing twice that volume of HOI, the ratio In which the molecules react must be 1 1 and the ratio of HOI product moleculesto H2 orCl2 molecules must be 2 1. This confirms the ratio contained In the equation. 

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