Avogadros Principle

In principle, Avogadro s number could be used to eliminate the standard kilogram mass. We could define Avogadro s number to be exactly 6.0221367 x 1023, then define. 012 kg as the mass of one mole of carbon-12. However, we can determine the mass of a metal weight with more accuracy than we can count this large number of atoms. 

In principle, one molecule of a chemiluminescent reactant can react to form one electronically excited molecule, which in turn can emit one photon of light. Thus one mole of reactant can generate Avogadro s number of photons defined as one einstein (ein). Light yields can therefore be defined in the same terms as chemical product yields, in units of einsteins of light emitted per mole of chemiluminescent reactant. This is the chemiluminescence quantum yield which can be as high as 1 ein/mol or 100%. 

Avogadro s principle rather than law, because it is based not on observation alone but also on a model of matter—namely that matter consists of molecules. Even though there is no longer any doubt that matter consists of atoms and molecules, it remains a principle rather than a law. 

Avogadro s principle Under the same conditions of temperature and pressure, a given number of gas molecules occupy the same volume regardless of their chemical identity. 

Avogadro s principle is commonly expressed in the terms of the molar volume, Vm, the volume occupied per mole of molecules ... 

Avogadro s constant The number of objects per mole of objects (Na = 6.022 14 X 102 mol ). Avogadro s number is the number of objects in one mole of objects (that is, the dimensionless number 6.022 14 XlO2 ). Avogadro s principle The volume of a sample of gas at a given temperature and pressure is proportional to the amount of gas molecules in the sample V n. axial bond A bond that is perpendicular to the molecular plane in a bipyramidal molecule, axial lone pair A lone pair lying on the axis of a bipyramidal molecule. 

Avogadro, A., F39, 144 Avogadro s constant, F39 Avogadro s number, F39 Avogadro s principle, 38,... 

Avogadro recognized the significance of this principle for the determination of atomic weights as his papers title makes clear Essay on a Manner of Determining the Relative Masses of the Elementary Molecules, and the Proportions in which They Enter into these Compounds. 

Historians have been much exercised to explain this half-century delay in the recognition of the application of Avogadro s principle for the solution of the atomic weight problem. It is not a part of this story to attempt a deeper explanation here, but it is appropriate to ask in a general way if anyone could have done earlier what Cannizzaro did about i860. For our purposes it is sufficient to offer two very broad general circumstances within which the many detailed factors may be subsumed. 

According to Avogadro s principle, at constant pressure and temperature, the volume is proportional to n, so, from Eq. 8 we can also write... 

Combining the above relationships and Avogadro s principle (under constant pressure andf temperature, equal volumes of gas contain the equal numbers of moleci csj nTo one equation wc obtain the Ideal Gas Law ... 

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